I use the bridge, middle, & neck about equally. I don't care for the quacker positions but will use them if the song requires it to sound right. I've actually modified most of my Strats to replace neck+middle with neck+bridge, which I find more useful. I play mostly on the clean side of the spectrum.
When I'm playing the Strat to get strat sounds it's the neck pickup for me, playing Semi-clean and fat.
I do have a HB in the Bridge of my strat that I use a lot - but I use that rather than switching guitars for HB tones.