yeah, if i had room in the kegerator for my primaries (without removing both kegs!) i'd definitely crash cool in the primary. the more you leave behind the better.
given what i'm working with though, i just let the beers clear on their own in the primary (for normal gravity non-belgians that takes about three weeks) then keg them and keep them cold for a week at least. i hook them up to the gas at the beginning of the week so that they're pretty well carbed by the end. if you do this you don't want to use the "shake the keg" carbing method, as it'll mix up all that stuff you crashed out.
after a week in the cold the first pint usually has some sediment (though not enough to make it unappealing to my tastes) and then it's crystal clear beer til the last pint, which gets cloudy again.