I think I've gone thru about 100 pairs of boots over the years.
I have the sidi air's with the external protection (B3 model maybe, can't remember, 300 bucks retail). I use them on the K1300S in the summer while I was commuting between socal and phoenix every weekend. They are not very comfy and actually hurt a bit at times, but I wore them anyways.
Recently I got the BMW all around boots. No perfs but I think they are just about as cool as the sidi's on the sport bike, noting that boots are more exposed to radiant heat from the pavement. If you ride the desert you know what I mean, it can get nasty at 115+.
I like the BMW boots for fit much more than the sidis, which i wore for years (probably did about 5 pairs of those). Luv the looks of the sidis (the waterproof model that you can wear to work, with the internal armor) and people at work tryed to steal them from me. they just ain't that comfy, for me, I gave em up (still use the perf's I have but probably won't buy sidi again).
One more thing on those perfs I have, the are even more uncomfy on the LT than the KS, I owned both bikes and used the perfs on both, ooouuuccchhh on the LT. Its probably just the way they fit me, I don't have italian tootsies I guess
The new line of sidi's is awesome too, sniff...