I have an e93 fsb and e92 rsb. If I cut the wheel and floor it from a dead stop the inside wheel does spin a lot more than it used to. However, on the track my car feels really balanced and the traction control never cuts in for rear wheel slippage. I had no problems even when floored coming out of some tight turns. I would do the same mods over again in a heartbeat. Now I understand I don't have a 135 and the extra torque might make a big difference with that.
AW, Coral, HID's, Afe Scoops and CAI, PBX, 264M's, 225/255 Ventus V12's, (BMW Performance: BBK, Illuminated Door Sills, Shifter Knob and Boot, E-Brake Handle, Steering Wheel, Front Strut Bar), E93 FSB, E92 RSB, M3 Rear Subframe Bushings, M3 Front Control Arms, HPA coilover kit (Koni Adjustables and Swift Springs), Steel Brake Hoses, Black Kidneys, Smoked LED side markers, LED angel eyes, Blacklines, Carbon fiber spoiler, Ambergones...