Like you have to be doing some stupid ass driving to slip the clutch with 5k on it and stock software..
Some GTI's have a rear main seal leak, which gets fluid onto the clutch mechanism, which can cause early failures and issues. Few threads indicating the clutch issues with the RMS.
I have had my APR stage 2 for 10,000 miles with absolutely ZERO issues. My clutch is still holding strong as well, although I don't romp on my car all that much compared to some!
Earlier build date cars seem to have less issues then later build dates in terms of clutch holding capability. One theory is that a clutch supplier was changed and since then, the cars have issues holding more then 40-50 ft/lbs more then stock.
No amount of perfect driving can erase the fact that the majority of clutch assemblies in the GTI and R are not designed to handle much more power then stock. Even if yours does not slip immediately, (or in a time span which warrants posting that your car is fine), you can be assured you will be forced to replace it far sooner then if you had kept it at stock power levels.