I ran a BT-016 front and BT-023 rear on my Superhawk for a while so they'd wear out at the same time. I'm running BT-023s on both ends of the Concours and just dropped my second set on. The stock -021 front lasted about 8k miles, and the rear less than that. The life was less than the -023's, and the grip was 'meh' as well. I rotated in a 180/55 rear that I had pulled off the SH when it went track-only at some point (just before my Iron Butt ride, about 8k into the first -023 full-size rear) because I had some tread left but didn't think it would necessarily make it a full thousand miles. That rear lasted another 6k, and the front went around 10k, so I'm COMPLETELY satisfied with tire life on these.
Currently running a stock sized BT-023GT front, and a 180/55 GT-spec on the rear. Yes, I know guys on the board say the 190/55 is better than the 190/50, but I'd argue the 180/55 handles just as well, is lighter, and is available in the GT-spec tire. I'm about to do another Tucson - San Diego - LA - San Diego - Tucson run this weekend, so I'll have more insight on how the GT-spec tires feel over distance and with a good chunk of 2-up riding as well.
One thing I'd note about the Bridgestones is that they're more sensitive to low pressure than other types of tires I've run, at least on a big bike like the Concours. Once the pressure gets down to 40 or so I notice the handling starting to go off, and anything below 40 can start the tire cupping pretty quickly. Get the pressures back up and it'll correct itself, but it's frustrating to lose tire life only because I didn't monitor pressures well enough... 'Stock' pressures are supposed to be 42/42 F/R, but I generally try and run 43/44 solo, and 43/45 for when I'm doing lots of 2-up. Once the tires come up to temperature that usually means I'm reading 44/46 on the TPMS sensors while riding.
Edited to add...
As for the original poster's question about the Pilot Powers, I'd recommend going with a sport touring tire. Not sure on what's up with the PR2/PR3 being 'illegal', but if they're not an option I'd go with the Angels or the -023's. Don't get me wrong, the pilot power is an awesome tire... you're just going to wear it out really, really fast on a Concours. I was getting 2500-3k on them when I had them on my Superhawk, and the Concours is 200lbs heavier and has more ponies. They'd grip well, but wear out too quick IMHO.