I just picked up an Aerotank V2 a couple days ago. I can't speak for the V1 air control valve, but the V2 is very nice. I would highly recommend it as an upgrade to a Protank.
As for the V2 heads, so far so good. However, I like to rebuild my Kanger heads and these ones seem like it would be next to impossible to rebuild
I ordered some of the V1 dual-coil heads in hopes that they will be as easy as the single
coils. Should be arriving today, so we'll see!