This was purchased for a client in Lake Tahoe to knock snow off of ski boots.  It is great for that purpose and would be, too, for mud.  It has a nice bristled pile made to stand up to such use.  The only thing to consider is the thickness of the pile as it was too thick for one of the doors that opens out to clear.

Pros: Great for snow and mud, easy to clean, heavy duty
Cons: A bit thick for one of our doors to clear