It sounds pretty similar to what happened with mine but mine worsened pretty quick and the car began stalling at random points. I did a fair bit of research into it and one of the things that kept cropping up was the cam follower (http://www.mk5golfgti.co.uk/forum/index.php/topic,8339.0.html) so may be worth checking as its pretty simple if you get the correct tools. Might be worth a check? My thread:http://www.mk5golfgti.co.uk/forum/index.php/topic,30046.0.html
Have I missed what your idle is like?See if you can log missfire counter for all cylinders at idle
I had a swine of an issue before xmas.long story short (its all in my build thread) it was injector 3. I had symptoms of duff plugs/coils/pcv and a couple of hiccups on idle VCDS was counting lots of missfires on cyl3 tho. New injector cured it