I just got a flat in my friggin rear (brand new!) Pilot Power last week. During finals week no less. I love the Powers and seeing as I just put them on, I obviously put another on the rear. If I could, though, I would try the Dunlop Qualifiers out for one particular reason:
The rear comes in a 190/55-17. This would certainly help the rear ride height problem a little (without pulling the shock or pulling the forks through the triple), while offering a good tire to boot. They sound about on par with the Pilot Powers, though they may wear quicker. Normally, though, I can't stand Dunlop street tires.
Also, I NEVER mismatch tires. Just my (and every tire manufacturer's) opinion.