Originally Posted by nospam
IMO yes, there is a big difference. The M wheel is much thicker, and the leather is perforated and much softer than the other wheels.
I am also not a fan of the aluminum colored trim on the non-M Sport steering wheels.
The M wheel goes perfectly with the heavier hydraulic steering, because it's very comfortable to hold, and you need that with the heavier steering.
A little tidbit about the thumbrest:
For cars with Sports Package, it will have a thumbrest if you don't have the paddle shifters. If you have the paddle shifters, the thumbrest will be gone.
On cars with M Sports Package, it will have a thumbrest regardless of whether you have paddle shifters or not.