Good info on the stock M5 FSB compared to thу Competition Pack one is here:
http://f10.m5post.com/forums/showthread.php?t=946237
https://www.bimmerfest.com/forums/sh....php?p=7938243 (post #266)
The CP option was not confirmed for the 5-series on the forum. This is probably because both M5 FSB + 550d RSB are 2mm thicker so introduce equal stiffness upgrade to the basic or M Sport ones:
Fronts: 24mm (stock MSport) --> 26mm (M5)
Rear: 14mm (stock MSport) --> 16mm (M550d/F13)
As for the M5 CP FSB it is stronger than stock M5, while search for the proper RSB upgrade (18 mm thik or so) returned negative. Such a setup with strong M5 CP front has no stiffness balance between the front and rear.