This is an old thread but thought I would some comments from our experiences. We have an '07 Starcraft 34RT 'off road' tent trailer that we tow with our '97 S/C'd 80. Its been on trips from CA to CO thru the mtn passes along the way as well as many trips to Lake Tahoe and the Central Sierra's.
The trailer is very large for a tent trailer - has the 'high wall' with the matching taller more RV-like appliances as well as wet bath with shower and 6-gal toilet, furnace w thermostat, AC on the roof, 4-burner stove and oven, microwave, built in inverter and 2 - propane tanks. Fridg is tall and actually quite useable for a tent trailer - works on AC/DC and propane. It has a push out - the dinette slides out and seats 4 men easily. Has king beds at both ends and a 1-quad front deck on the tongue. I installed a lot of storage stuff so its heavier than stock now. GVWR on these is large for a tent trailer at 5k GVWR IIRC. There is an even larger Starcraft that someone mentioned in the RT series - the 36RT. Its double axle permits a much larger deck out front and 2 quads but the GVWR gets quite large. The 34 RT and 36RT shared nearly the same interior build out except that the 36RT had a hard-wall shower / wet bath - it would fold down in on itself and was not too bad if that was important to you.
Our 34RT has a 35 gal fresh water tank but no gray water tank -- I fabricated up the plumbing to dump gray water in to one of those 30 gal blue tanks on wheels -- a whole lot easier than buckets! (IIRC, the '08 or '09 came with a 35 gal gray water tank after they re-arranged the shower location. The clearance for these trailers is quite good but they have done hardly any work to protect the tanks under the floor except for the natural protection of frame rails -- ie. no skid plates - everything is exposed.
All in all, the 80 tows it quite well. It does slow down quickly on the hi mtn passes but no more so than my bro in law w their stock Suburban and their std Jayco tent trailer. I do have the load stabilizers on our hitch -- makes a huge difference to be able to tx some of that wt forward on the 80. Trailer brakes as well. Gas mileage does not seem to be affected much when I tow - maybe a 1/2 mpg less on certain trips. (We have a scan gauge). With the setup, it easily runs at 65 mph with mild grades in w OD off. Shifts down to 2nd on the passes, tho - I work hard to keep it at 2500 rpm or so and watch the temp gauges. (We have done all the usual upgrades to the cooling system that one does for the S/C'd 80's). Per the advice given elsewhere, I do like to tow with the OD off to give the AT a break at the expense of gas mileage.
The stock clearance on these things is very nice - its got 16" rims. Shock absorber on ea side and the stock 'lift' place it at a nice tow height relative to our 4.5" lift on the 80. I have never attempted hard core trails with it but several forest roads, etc. Its big enough to avoid the narrow trails for sure!
Build quality -- in many ways its a well engineered trailer for and American RV company. But, the folks building the Starcrafts of this vintage seemed to have a lot of QC issues - most of which I fixed in the first year and some have been dealt with over time. I have found in the lower-priced trailer RV community (sub $30k) that this is common but I think I may have had a few more issues than most. I certainly repaired far far too many things that were due to very poor union workmanship! -- one screw holding the oven in-place, hoses cut so short and installed so that they were kinked closed, wood work that would cause any normal cabinet guy to blush, etc.... all fresh from the factory. It is strange tho to find great workmanship in certain areas and none in others - wonder what happened to the QC guys at these plants in Indiana...
Engineering -- my 2 cents is its nice for what they are and realizing they are not a Kimberley from OZ! I chose the StarCraft over the Coleman E3 primarily because of what seemed to be a beefier frame design, better roof lift mechanism, 4" mattresses on king beds, the high wall sides and appliances (!), what seemed to be a better one-pc aluminum-laminate roof and fiberglass laminated walls and a bit better set of specs on capacities. The inside height is really tall -- a 6' 6" guy would have no problem with this trailer! On other hand, since everything is so tall on a 34RT, it makes it that much harder to set it up for us average ht guys! It is absolutely huge inside - I frequently have visitors comment that their big motorhome is smaller inside than our tent trailer... When these things open up, it does feel large. Have camped many times w 4-6 adults in it and it works well w the push out dinette.
In retrospect, no issues from my pt of view in towing these larger tent trailers at all behind an S/C'd 80 or a 100 IF you have trailer brakes, load stabilizer hitch and a well-maintained rig. A lot of miles on the CA and CO mtn passes under my belt. Now, IF I had a big Excursion as a tow rig with a big turbo diesel in it, it would be that much easier.
Ours is likely to be sold - moving on to something that requires less work to set up. As someone mentioned, for small families traveling during the day and camping for the nt, the set up / tear down cycle really wears you out! For 2 to 10 day stays, tho, and its just fine. It just seems no matter how hard we try and no matter how much storage space I fabricate in to the frame, it takes time to break camp - always shuffling stuff from one place to the other. These new tent trailers seem to have no outside-accessed storage bays anymore! Told its because they had too many warranty claims on leaking compartments. Its great to have the big decks on the fronts of these trailers but you have to clear enuf of the deck just to put the beds up and place the poles! I miss the outside compartments that my parents old Jayco had - two doors on opposite sides let you get at stuff rom either side - nice. And, how about a fridg that you can access when the trailer is collapsed! Its hard to find a floor plan in tent trailers that does that and its really easy to use the hallways to load all your gear even if you have a deck out front -- ours has lots of cabinet space for a tent trailer but you still have all your clothes and gear... guess it depends on what you want.
I have also found that these or maybe any camping trailer needs to be maintained and inspected and fixed -- screws loosen up, staples on panels come loose and on and on. You have to take the time to stay on top of it. You can make a lot of improvements if you are good at that stuff and make it easier for yourself.
Also was surprised to see the maintenance schedule call out the need to tear down and re-grease your axles every year! I finally did on mine after the 3rd year and found out why - the grease they use breaks down. Noticed on the Chinese-made bearings the signs of scoring already. So, sourced some American made bearings and did the rebuild. Bought a spare set of bearings and seals for the next time - always takes time to get trailer parts!
Tires on these things are critical to watch and inspect. The Chinese made 16" tires on ours de-laminated in less than ~15k miles and less than 3 yrs old even with tire covers on them! Still arguing with the tire mfg to get the warranty claim settled on them. Went with non-Chinese tires instead and have worked well since.
I did seriously consider back then on buying a std tent trailer and then doing a lift on it. Looked at a lot of frame designs and talked to guys about it whenever I could at RV shows, CG's etc. I found that all the 'regular' tent trailer I managed to see under were made with very light duty frames, axles and suspensions! It almost scares you to see what they put under em! Where Starcraft seemed to do better w their RT's is in their frames and axles - at least compared to the US domestic mfg's. So, I started pricing not just the cost of a lift, but a new larger axle with shocks and a leaf spring and brakes, etc. and then add in the cost of either replacing the std tent trailer frame with larger cross-section channel or working hard to reinforce what was there, plus beef up the tongue and add the extras that were not part of a std TT and I realized I had more than paid for the Starcraft RT series of trailer. You have to remember that a std tent trailer comes with the short wimpy trailer jacks and when you lift it the little leveling jacks no longer touch the ground. So more $ to buy and install (4) new heavier jacks - and the list goes on from there. Again - that was based on my set of circumstances of buying a new std tent trailer vs buying a new offroad tent trailer and having to pay for some of the fabrication work to be done where I lacked the tools and shop space -- your situation may be completely different. But, its more involved than it looks at first.
We are glad we bought it - have had it since '09 - worked reasonably well. BUT there are a lot of Cons and Pros - and did I say Con's .... Have to decide what works for your family and rig. Hope this helps others -- wished I could have found have found this kind of discussion back in '05 when we were starting our search!
Sorry for the long post -- Good luck!