Well, i just changed the pads w/o cleaning the pistons and all that. I did that last week when i had the wheel off (tho not real thuroughly) so i guess it'll be ok, tho as i said if you ruin the seals you have to buy a whole new caliper/bracket assembly at almost $600 after tax !
Anyways, last time i changed the pads it was with the wheel off. This time with it on, and while it took about 20 minutes thats about 1/3 or less the time i had estimated. One of the very few times anything i've done to this bike turned out to be much quicker than i thought.