Let me put it to you this way, here is my gig rig:
The blue JCA100H you see there has been gigged with for at least 2 1/2 years now, with zero issues, and I bought it USED.
Can't. go. wrong. $500 seems a bit high unless it is the HDM model. Stock, the 2 channel Jet City amps are very similar in sound to the Soldano Hot Rod+ (Seen more than one account say this, but I can't say personally). Plus, I just performed the Depth and "SLO" mod on my JCA100H, and it basically specs out the caps, resistors, and pots to the same values as what's on a Soldano SLO. Thing fucking rips now.
Some people like to bag on the Jet City stuff because they use PCB, board mounted tube sockets, board mounted pots, etc. However, I want to remind y'all that the Peavey 5150 series that everyone says are built like tanks . . . . also have PCB mounted pots and sockets
Mikey and Doug at Jet City are great guys to deal with if anything should go wrong, or even if you just want to ask around.