I don't believe Mtech are producing the v4 anymore, can only guess why.

Ecu is ok, at the end of the day it's a megasquirt ecu in a posh case with out of date firmware, I have used one and we run it on the latest MS firmware with half decent results.

Like most things you get what you pay for, for a budget ecu its acceptable but as mentioned you can just buy the ms equivalent for less