another idea
a couple tapeops ago (#37, iirc) was a FANTASTIC interview with michael brauer and bus compression. in a nutshell (and not doing the article or interview any justice), instead of compressing the entire mix (on the stereo mix bus), rather he splits the mix into several segments (low end, guitars, high end), etc., and busses them out and applies different compressors/compression schemes out to each of the busses. namely, in some cases, you might want a more compressed low end but open high end, etc. of course, he went into what compressors he normally uses for what duties, you name it. the pictures of his compressor racks were astounding.
it was extremely enlightening and i'm looking forward to giving it a go sometime here in the future. it would definitely be a nice twist to simply slapping a compressor on the mix bus and just letting it ride. and it definitely keeps things like the kick from making the rest of the mix pump, etc.
i generally avoid as much "mastering compression" as i can when i'm mixing. i just don't like my music/mixes very squashed--personal preference. still, i DO find that i want them to be listenable to in the truck without having to crank the dial to 11 (which kills me and the speakers when i forget and turn it back to the radio without turning it back down first). it's a matter of squeezing only a couple of dBs, and in my case, it's usually "just" the transients on the snare that catch most of it anyway.
in the case of clients, it's hard to get non-engineers (and musicians in general) to understand WHY what they're hearing from an unmastered mix is so "quieter" than the dreck they buy at the store. i'm all for "preserving the integrity of the music", but i'm all about making my clients happy too, and find that there is usually a middle ground--that extra couple dBs is generally enough to make everyone happy, but some folks just won't be til it's been pounded into one loud mass of gunk. if they're absolutely insistent that you squash the crap out of their music, i would far rather give them a "good, unsquashed" mix and refer them to a professional mastering house than killing it myself.
wade