I have a Surly Karate Monkey, currently set up with a single gear and Surly's (spindly) straight-blade rigid forks.
Generally it runs 2.2"-2.4" knobblies and is used a mountain bike and also as my (short distance) commuter. I've not been doing events so far this year, it may get some XC racing action at Beastway and is likely to be my bike of choice for HONC, CLIC24, Bikefest and possibility HtN, not that I'm exactly a pro-race whippet. Yesterday I did about 80 miles on it on road and the south downs way, running 42mm slicks. I'm considering doing a bit camping tour on it over the summer.
The Monkey has rack and mudguard mounts, although there seems to be an issue using a rack and disc brakes – which I dare say it bodgeable.
That said, I had a rigid Kona 10 years ago with 26" wheels which would have easily done exactly the same range of jobs. I'm not going to say with any confidence that the Monkey having 29" wheels makes a blind bit of difference. It is a lovely bike though.