Heck yes!!! This is alot of fun and gives you a great sense of accomplishment. Mark I'm signing up for the Mud Ninja again as well. It's in Ohio and it is the hardest and best so far. It kicked my arse up one side and down the other.
If Warrior Dash was a 6 on difficulty I would give mud ninja a 9. MAJOR HILLS!!!
I did 4 races last year.

Mud Ninja-tough, muddy and fun!
Warrior Dash-not so tough but muddy and fun!
Capitol City River Dash- excellent course, lots of mud and great accommodations for getting clean! Not tough but a great time!
Extreme Rampage-not tough, kinda boring but fun with your kids or folks who need a easier course.
I will be signing up tonight for both.