Evidently I'm in the minority, but I always use the chain brake, particularly if I'm cutting around other people. It really doesn't take any particular effort once you get in the habit of using it, and I like having it locked when I'm not actively cutting. I don't even think about it at this point; it's simply second nature. Much like the safety on a gun, it's no replacement for good saw handling, but it's another layer of caution, and personally I think it's a good practice to get into. Yes, I even start the saw with it on (and I like the fact that the chain doesn't spin like mad when the saw fires on high idle). I'm sure it is a little wear on the clutch at start-up, but I blip the throttle very quickly after it fires, and I doubt my start-up procedure causes as much wear as bogging the saw and partially stalling the chain even one time in the cut which I see guys do with regularity. The only way the chain brake will hurt the clutch is if the chain is trying to spin, and it shouldn't do that at idle unless your idle is set too high or the clutch springs are weak. In any case, I haven't burnt a clutch yet and really, even if I did, chainsaw clutches are pretty cheap in the big scheme of things...
Also, I don't see how you could really burn out a properly functioning chain brake; the brakes on all the saws I run won't slip even at WOT. If it doesn't slip, it won't burn the brake. The clutch, sure, but not the brake.