I keep reading interviews with the producer/ mix engineer heroes of todays mainstream pop music, and it seems that some of them use limiters at the track level througout a session. I dunno, it just seems wrong to me to clean every track of transients before they even make it to a buss, but it seems to work for them...
I usually keep turning tracks down, keeping an eye on the level of the busses, and only ever apply limiters (to the busses) at the last stages of a mix.