Can't say whats good or not on the GT, I've only had the KS.
But, I just rode to MI from AZ last week (2500 miles) on top of a few other trips to NM and TX thru the mountains with the PR3's.
I've got near 6000 miles on them now, so its time to comment.
Good handling in the rain!!
Actually, good handling all around.
But, overall, it does feel like a "heavier" tire. It doesn't fall into the turns like the more aggressive tires but its not bad.
I would recommend folks try these if they are all-weather riders like myself.
Oh yeah, I was also riding in heat, up-to 118 in June already (CA/AZ) and its been hot, doesn't seem to make a diff.
By the way, enough tread left for another K or two easy, not sure what they'll feel like at 8k (Mich's seem to die before they lose all the tread, ie, tires get hard) but will keep you posted.
I do plan to buy these again for the next set. I'm not a big Michelin fan but I have to say, I do believe these may be some of the best tires I've ever run on (I'm a Metz fan, or was).
And that would cover some tires (LOTS of tires), with near 90k on the K1200S, traded in for a 2011 K1300S (27k miles on it) and the RIP'ed K1200LT with 135k on it when it was quickly disassembled by the road, brush and acrobatics from a 70+ to Zero slide, heheh.
I won't count the FZ1 tire miles before beemers, cause I was running bridgestones and Metz (50k miles) and its generally a diff bike.
Whats funny is a couple years ago I was pulled over in the pouring rain, in the desert, at 120 (radar) with Metzlers (probably Z6's or M3's). The K1200S was like a rock on the highway. He let me go, I'm glad he didn't pop me at the 130 I was cruising at, I was wet and cold so I was in a hurry, the hot sun was only 60 miles away
So now I'm like a bit caddy at 80 in the rain/wet roads, I must definitely be getting old-faster instead of riding-faster
one more thing...the PR2's, I was done with them by 6k due to the strange wear pattern you see near the end (very much like the Metz M5 did to me). The PR3's, so far, nada, did I say I really like these tires??