I don't have allergy to RSA amps, I just happen to not like 20% THD from a headphone amp. Kinda defeats the purpose of one when all it does is limit volume and add distortion.
The HD800 is picky but being used to the SR-007Mk1 I can't say that it's a bad thing. They simply need a good, stable amp to drive them which can handle the quirky impedance behavior. Now this excludes 95% of the amps out there so people swing the other way and use badly designed garbage such as the Alo Studio Six and Leben to mask what they find offensive in the transducers character. One could argue that this is defeating the point of buying them in the first place though...
It's the same crap as with the 009, so many think that simply adding distortion will fix what they find wrong with the transducers.