One thing to note though, there is a documented problem with Greenstuff pads leaving uneven resin deposits on slotted rotors, which leads to an annoying vibration which feels like warped rotors. It's easily fixed by pulling the rotors off and sanding the resin off, but it's a bit of a pain. If your existing rotors are OK (ie above minimum thickness) I recommend leaving them.
F**k! I had that exact problem with my Greenstuff pads and thought the disk was warped. Only when stopping from high speed, so I didn't notice it tooling around the city at 60kph (which is 90% of my driving) . Sold the car since then, but it's nice to know what the problem was.