I was running bluefin stage 2+ on my mkv GTI . Never had any problems and certainly not here to bag bluefin, I still think its very good value for money. I just felt it didn't have the punch I was looking for in 3rd or 4th. I'd read similar feedback on the UK forums when it came to stage 2 tunes with bluefin, so I thought it might be worth looking into alternative tunes. The guys in the UK were all raving on about how good the REVO tune was, but unfortunately there's no REVO in WA. Then I started reading some great reviews about Viezu, and as luck would have it, Simon and Greg made the trip West. So, I took the plunge, and now after a couple of tweaks here and there, I have to say that I'm very impressed with the Viezu tune. After the tune had time to adapt, the first thing I noticed was how responsive and smooth the tune was in comparison to the bluefin tune. Really punchy all throughout the rev range, especially in 3rd and 4th! As a bonus, I'm even getting better fuel economy!
So was it worth forking out the extra dosh for another tune, I definitely think so, car feels awesome now!