I am assuming it is the EVC 5 (or EVC EZ?)you are talking about
I can only speak from experience - I used to have the EVC 4 (which would be the jdm EVC 3 unit).
Assuming they havent changed the design, it runs off a stepper motor which is more reliable and more responsive and doesnt spike as much as a solenoid based system would.
In terms of installation, theyre fairly straight forward. I had one in my GTS-T 33, and I really had no problems with it.
It held boost very well, never spiked. Easy to operate, etc