I browsed through a bit and didn't see a lot of technical comments. I have extensive experience supercharging Tundras and a couple LX570s. My personal Tundra has 305k on it and been running a TRD supercharger the last 90k.
You have a variety of options, Magnuson 2650, Harrop 2650, and (arguably) Whipple. I would NOT get the Whipple, lots of quality control issues and I currently have a Whipple in my shop that just came back from them servicing it and there's stuff wrong with it. Plus their support seems to be going away.
The Magnuson and the Harrop are similar, really the question is the overall package. Harrop has two offerings, "stage 1" which is the basic setup that doesn't "require tuning". And "stage 2" that comes with injectors and a tune and maybe some other stuff. A benefit of the Harrop is that it comes with a harness that moves the IAT sensor after the rotors so you get post-boost IAT values, vs the Magnuson that uses the stock MAF location IAT so you don't see the true temperature of the intake air. I think that's kind of a minor point, but should be noted. The stage 1 is not inherently bad, but the lack of tuning they recommend is stupid at best. I have looked at truck datalogs before tuning them and with the blower and stock tune there is a lot of knock retard happening, additionally the stock power enrichment (when the truck starts dumping fuel to richen it out) doesn't happen until 70deg of throttle angle, and yet you're going to enter boost around 40deg so if you're cruising around you could be well into boost without richening out.
The stage 2 comes with a tune, but frankly I would not run any manufacturers tune, the aftermarket is much better and places like OTT even have CARB compliant tunes if that is required. However, the stage 2 does come with DW650 injectors which are very good and what I recommend all higher power setups go to, so the fact you get a quality and large size improvement injector is huge. And I think you get a DW300 fuel pump, though I forget. You do NOT get an intake though.
The Magnuson 2650 is the most well rounded and complete package, it comes with a tune (again, would still recommend an aftermarket tune but the newer Magnuson tunes are much better than the old TRD tunes), it comes with 535cc injectors (better than stock but not by much), it gets a fuel pump but not a lot bigger (just enough to support the 535s, so if you ever upgrade to larger injectors you need to upgrade the pump again---I would recommend getting the DW300 pump for $130 or whatever and just install that so you're future proofed from dropping the tank again), and the Magnuson comes with the best aftermarket intake setup which is a 4" intake tube and uses stock filters and is very high quality. You can buy the Magnuson intake separately through Superchargers Online and it is a common upgrade for the other superchargers. The intake itself isn't about making power, the issue is the stock sensor can only read so much airflow before it maxes the sensor out, and a larger intake has more intake area so the area of air being measured from the MAF becomes smaller relative to the total intake area, so you read a lower voltage at more airflow. This isn't a catastrophically critical issue, worst case the truck throws a code that the sensor is maxed out and nothing else happens and it's only at high rpm, but the point is just that the Magnuson comes with this intake and no other supercharger does.
Both superchargers have pulley upgrades (Harrop sells them, and I make Magnuson pulleys) and the pulleys are four bolts to swap out. Probably not a big concern, but for higher altitude people a pulley is highly recommended since you see massive power losses with a supercharger due to altitude.
In summary, both have tons of upgrade potential. If you do not plan to upgrade the boost much/at all, then the Magnuson is the most complete kit. The Stage 1 Harrop I would not even consider, stock injectors and no tuning is dumb. The Stage 2 Harrop comes with larger and very much usable fueling upgrades over the Magnuson, but lacks the intake. If you want to push more power than a stock supercharger, the Harrop comes equipped out of the box (minus intake) for that. If you want to push more power, the Magnuson needs the injectors and pump upgraded which is more expensive and intensive than just upgrading the intake for the Harrop.
The Magnuson and the Harrop are both extremely reliable. You can't go wrong with either, and performance wise they are nearly identical and use the same Eaton 2650 core. Really the question is pricing, and what ancillary items that are included are more beneficial to you. If you get the Magnuson, I would at a minimum do the DW300 pump and throw out the Magnuson pump; if you get the Harrop I would get the Magnuson intake. Either of those configurations is a very good starting point with potential to easily push more juice if/when you want.
Tuning is a whole other conversation, OTT is a very common recommendation and has CARB compliant tunes for the 5.7. Many others tune the trucks too. Depending on the place you might be able to use the tuning hardware included with the superchargers, or you might have to buy separate hardware from HP Tuners or VF Tuner. Aftermarket tuning generally runs ~$600+, the Magnuson and Stage 2 Harrop come with tunes from the OEM, but they are somewhat limited and obviously are just canned tunes, but they are better than nothing.
As far as failure modes you're looking at, the superchargers are very reliable and don't generally need maintenance until 100k and just get an oil change (requires removal of the blower). The supercharger can be gone through and rebuilt. The 5.7 engine is known to have ringland failures if the pistons get hot, because of that we generally run the 5.7 richer than most boosted engines to keep the pistons cool and avoid issues. Personally I like to richen out very heavily right as the truck enters boost so it's very conservative. At stock supercharger boost levels, the Magnuson 535cc injectors are fine, for more boost you'll want 650 or higher flow injectors and a fuel pump to support it. Besides that it's just tuning to command more fuel to keep the pistons safe. Lots of high mileage superchargers out there, and if you're just stop light racing and cruising they are very reliable boosted engines, just give it a lot of fuel and a good tune.
