Thanks for all the replies guys.
I found the ram Air kit to be pretty easy to install and looks decently nice, although not a fan of the oversized kit with a millions of jubilee clamps.
Yeah, you're right damnit. I did end up ordering the bigger one yesterday, mostly because it seemed like that version did have something of a heatshield for the upper part of the tubing. Luckily it's not too expensive, if the sound is too much, I'll just flog it on Marktplaats (Ebay for Dutchies).
perform a simple smoke test for leaks
always choose an OEM proper revision DV over any aftermarket one (inc GFB)
use VCDS , scan for fault codes + live log boost values to see if it all looks within normal ranges (your friends gti may have been mapped without him knowing, as opposed to yours being donw on power)
Smoke test is scheduled for Friday. As for my friend's GTI being mapped, yeah, I did think that most likely at first. Still, my new DV did make an improvement. However, it may still be that the difference I'm feeling is due to his being mapped.
I should probably have it tested on a dyno somewhere to be sure. Too much guesswork for an amateur like me. It's fun though, what a great car, regardless of a few niggles here and there.
Our chain tensioner failed the first two weeks we had the car, I was blinded by the fact that the belt had just been done! Thankfully it turned out fine as we were still under the dealers warranty and I turned the engine off as soon as I pulled over. Make sure you replace that camfollower too although I'm sure you've done that already, another killer to these cars.
Yep, cam follower is replaced. However, the first time my mechanic had a look (on my request), it had a hole in it. Camshaft is probably already damaged (hopefully not too badly?). We've now added the cam follower as an annual service item so to speak (since they're probably gonna go a bit quicker on my car).