Well
The clips sounded awesome, and nothing flash was done to record them, its just close miced into prosumer gear in a home studio. Impressive.
I've had some exchange with James, and he speaks the right sort of speak for me to believe hes no bullshtter just pedaling his wares, and hes an extremely helpfull chap thats all about tone.
A previous powerball user, current chimera user described the exactly the differences I want - less sterile, more dynamic, but still tight and aggressive as hell
Opinions I can find are unanamous on their awesomness and versatility (including performance at low volume)
And on the clean - all the twin channel amps have the same Halo clean channel, which is reportedly very good (but I only care a little bit about that - I think the PBs cleans are superb, and I'd have that as well anyway).
All in all, I havent found a single bad thing about the amps or James Peters. Everyone loves them and him (the latter being really important for custom stuff, for me at least - a big part of the reason I use BKs almost exclusively, and that I chose legra over other custom shops I looked at is because Tim and Bob are such pleasures to deal with, and James seems to be in the same mould)
Add to all this the fact that its hand made, chasis mounted, point to point wired amp for ~£1500 inc shipping, and you have a winner. Obviously one takes a huge chance with ordering unheard and untested, but thats where carefull consideration of all available information comes in, which has worked out for me very well before.
