From the posts it seems as though the replacements as worse than the ones in the car for some reason. The only problems with my carpets are the fact that the fit on the passenger side is a little bad as there is a small area of soundproofing showing. This has been fixed by other owners using black plastic.
The only other problem is the clutch pedal hits the floor and wears the carpet, 150000 miles on mine and it hasn't got any worse since it started.
After all the problems others have had with new carpets being fitted, I will just leave mine as-is.