We see a lot of wheels. Just yesterday, I pulled into the BP station at Falls and River in Potomac (home of the world's coldest water fountain - inside the right hand bay next to the door to the office) and of the 9 bikes in the parking lot, I'd built 4 of their wheels. That kind of stuff happens with some regularity, so you wind up seeing a lot of wheels and checking in on them. One thing that often concerns me is that it's always the rear wheel that's got more brake track wear than the front.
We had a customer contact us a few weeks ago and say that while he loved his 58s, an injury pretty much precluded him from doing any more racing, he was getting more into charity rides and gran fondo type stuff, and could we do a swap for some FSWs. This is the kind of thing that really benefits everyone, so we said yes, and he sent his wheels back to us. For how long he'd used them, they looked awesome (I put about an eighth of a turn on one spoke, mostly because I felt like I probably ought to do SOMETHING), but the thing that impressed me most was that his rear brake track literally looked brand new. The front looked like it hadn't been used as much as the front I've been using for about a year, but it showed wear. The rear was spotless. Someone who really knows how to brake! BTW his wheels already have a new home.
Next time you are standing by your bike, do this simple test: grab the rear brake and push the bike forward. The rear wheel skids and the bike goes forward largely unimpeded. Now grab the front brake and push the bike forward. The bike goes nowhere and the rear wheel lifts off the ground. The front brake is (scientifically speaking) about a Brazilian times more effective than the rear at slowing you down or stopping you.
Assuming that most of you did the same dumbass thing that I did when I was a little kid and slammed on the front brake real hard and went flying over the bars one time, then your hesitation with the front brake is more than understandable. However, you really need to put that behind you. Gently push back as you apply the front brake and your weight will stay balanced exactly where it should be, and you will slow down faster and more effectively by far.
Two caveats - 1) overuse of the front brake on a cross/mountain bike may lead to you sucking and/or needing new teeth and 2) beware the front brake in turns. Beware both brakes in turns, but especially the front. A rear wheel skid is often a recoverable deal, while front brake skids almost always result in you making a tarmac inspection. Which is a big part of why you want to brake BEFORE the turn.
If it hadn't been totally raining on Saturday we would have had a nice video of descending and braking, but alas the video looked a lot like wet lens and spots of color. Good braking fundamentals become even more important in the wet.
But if you're doing it right, your front brake gets most of the workout.