I bought one, but being completely honest, I don't notice a massive difference.
Maybe I was expecting night and day?
I'll describe where I noticed the difference.....
When I bought my ed30 it was already Revoed and had a revision D in it. Literally a few days later I took it up for remapping and a DV+ was thrown in as a matter of course. All was good in the world.
Roll on 6 months or so and I switched to a Revision G, just because everyone was raving about it and I had a flat spot appear, so was trying to rule out the DV.
Literally, from the first press of the gas in 1st, the car felt less responsive with G in it. And after a day's driving around, I took it out and put the DV+ back in. Responsiveness restored! Like you say, it's not a night/day difference, but it's certainly noticeable.
It's clear to see why that happens when you watch the vid! The OEM DV is either open or closed, so any residual over boost left in the pipework and plenum after a part throttle dump that could aid responsiveness, gets dumped off. The DV+ keeps it there
Once you're in boost though, I agree, no difference over stock G. It's just getting into boost feels more pleasant with the DV+.
Having said that, I might bung my G back in this weekend just to make sure I'm not imagining things