Ever since one of the releases (pre 2.5) I fell victim to the high-CPU / audio clipping bug. Never since then has Traktor worked properly. I’ve had a couple shows where I had horrible clipping.
If I disconnect the S2, CPU utilization goes way down. I still don’t feel this is a hardware issue, it’s all attributable to one of the updates from a while back, and none of the fixes have worked since.
What year is your MBP? I am using an 09 aluminum MB (non pro) with the base processor and I have no problems. Even when just for fun i have both turntables running, all fx units on, and all 8 remix decks playing, the meter never even gets to halfway. Could you maybe have a bad driver?