Rev D didn't leak on my ED30. Think it's running 1.3 bar boost (0.9 standard).
I've used the original orange one, D, G, and a GFB DV+. The latter
seems to give a slightly better off-boost throttle response but some of these mods are a bit psychological aren't they? I.e. you've paid the money and fitted it, therefore it MUST be better, right?
The main benefit of the GFB part is it's strength in high boost applications. It's an all metal + O-ring construction. Nicely made bit of kit.