Th xtend clutch kit/xtend pressure plate is just a slightly modified OE pressure plate and OE organic disc, at least it used to be, they just called it something different. It doesn't hold much more than stock (+15% holding capacity over stock). The "performance clutch" aka " SRE (Sachs Race Engineering)" version uses the Race pressure plate. The organic disc is going to have much better street manners than the paddle disc, but the paddle disc will hold a lot of torque but is not known for having great driveability.
Hope this helps. We have a local MK7 R customer which we installed an "xtend" kit on a MK7 Golf R and slips on Stage 2. I do not recommend it if you plan to go over stage 1. Not even confident it will maintain clamping force on the high torque stage 1 files.
Thanks,
Greg