We quite often get customers in for software upgrades after they have tried an alternative product which has caused problems. They will discuss the problem they had with the other tuners software and usually they have then had the car flashed back to stock before coming to us.
After we have flashed it with our own software or Revo we fully expect to have them back within a few days complaining of the same fault, usually resulting in a refund and reflash to stock, this is all part of the tuning business.
What this tells us is that the fault is actually on the car and the software is just highlighting it, and when tuned the increase in power and torque is just enough to cause the fault. Most tuners software for each given engine will have the same/very similar calibration and the end user may have the ability to alter some parameters (i.e revo sps tool). If the fault was with the software its likely that all of the cars flashed with that software will have the same fault, however I have flashed 30+ 2.0 tsi cars with none of them experiencing any issues that the OP describes.
Clutch slip is a fact of having a mechanical manual clutch, not any fault of the software. The other faults sound like ignition problems to me, i.e spark plugs and coilpack issues. These problems are often highlighted with tuned cars, I couldnt count the amount of healthy running 1.8t's and 2.0 tfsi cars that I have had in for tuning that have a plug or coil give up shortly after. This isnt a sign that there was a fault with the software as once replaced for healthy items the problem went away and stayed away, it was a fault with the component itself.
For cars to be tuned they should be in good health, the fact that they are standard and running fine isn't an indication of every component being healthy.
