Have the HFS kit on now. Haven't wheeled it yet but drove it around enough to know that I need to get the caster corrected before attempting to head 50 miles to a trail. It is all over the place finding road imperfections. Was not bad at all until I lifted it. Ball joints are pretty tight, just need seals. Drag link is rubbing HFS shocks too. I have a Sag pump and a mini truck gear that should fix that. I was thinking that the front is still not level with the back, so I am going to get some slightly longer (1.5 inch) greasable shackles to tilt the axle back a little. Should be better anyway. If it isn't I will probably add some small shims also.
I have HFS 2.5'' springs front and back, they ride pretty nice! Make sure you do all your research on shackle height etc. before ordering so that you cruiser doesnt sit weird. Havent had any problems with wander or death wobbles, but seems to be a problem with the 4" springs. Shackel reversal might help though, not sure. Did you get your reversal kit from Man-a-Fre? If so, maybe just go with their springs too so you dont have fit issues. Good luck!
I have heard a lot of good things about the HFS springs so I bought the 4" kit and 1.5" shackles. It looks like good quality. I spoke to Uno-Racing on the board and he said that he needed to get the caster correction shims so I would plan on that.