Thanks for the replies, guys. I forgot to include the Dunlop Winter Tread Run Flat in 175/60-16 I ran on the late, great GL1800HPNA as an additional prior DS tire. It was just slightly narrower than stock and any difference in behavior was imperceptible to me. And yes, I was running TPMS (Doran 360m). That system was later moved to my Valkyrie.
Jess, if you're comfortable on the GATT, I'd bet you'd be comfortable on any other of the popular candidates. I've ridden two Valkyries with the GATT and won't consider that tire for myself. It's way too square for me. It requires the most steering input I've experienced and after riding behind several for many miles, I don't like they way so much of the tire lifts off the road in turns.
Thanks, TJ & Pappy! I feel the same way about what BonS says, too.
Thanks for the feedback, Bon. Definitely food for thought. The only tire we've torn the bead of on installation was an oem rear for the 'wing. I was leaving the next day on a trip and the only other tire on site was the Dunlop, my first DS.
RDKill,
I wouldn't call 420 UTQG a long wear tire. But then I probably would consider a 140 UTQG Extreme Summer Performance tire a track tire, not a street tire.

At 420, it's a considerably lower number than the Altimax or Ziex 512. I think they were both 540. For reference, the GATT is 640. The old Michelin HydroEdge was 800!