Nice Stumpjumper. I hope you have a lot of fun riding it!
I rode with a roller cam brake under the chainstays for 12 years. On our steep terrain I was willing to trade the better braking control and stopping power for the increased mud accumulation.
I rode in the mud all one winter, then had to ride in my own erosion gullies all the rest of the year. After that I stay off the trails when they are at their muddiest.
Brent