I would say OE personally. 
Why? Have you tried the GFB DV+ and didn't like it? 
I looked at it but decided against it. I was talking with a company who had more experience of this than me and the evidence seemed to suggest it might not do anything more than a serviceable OE part would. It's only a personal opinion and if I were proved wrong by empirical evidence I'd probably go and buy one. On the face of it they sound like a great product but as is the way with many of these tuning goodies there is a good deal of marketing involved. I've never had any boost issues apart from the usual KO4 compressor surge. It was for this reason that I started looking at these and I also found a YouTube video where this chap in America believed it solved this problem. When I understood more about what causes compressor surge on the KO4 I felt this information was inaccurate so I left it. If it did solve the problem of compressor surge I'd buy one tomorrow but I don't believe that it would. I'd be interested to know for what reasons these are bought and I'd almost be happy to realise that I'm missing out on some tuning goodness but I'm really not sure I am. I'm not saying that it's either c**p or rubbish but more that I remain to be convinced. 
I replaced my rev G DV for the GFB DV+. The diaphragm of the rev G was intact when I removed it. I can tell you that I can feel a faster boost on WOT and much faster boost response when on partial throttle to WOT.
If you look at the design you'll get why. The DV+ seals as well as any working rev G DV does but due to the piston design it won't rupture with time. The interior springs will make the DV+ close much faster than the rev G DV so the system will lose less air when you apply pressure to the throttle pedal.
I'm happy with the money spent on that part and I think you're indeed missing out. Since it's so easy for you to access the DV, I'd suggest see if you can let someone lend you a DV+ for you to try before buying. Like a test drive with it.
