So, as some of you know, there is a 'B' designation used on the 180/55 PR2, and the 180/55 & 190/55 PR3.  Michelin says that it is "specifically designed for loaded sport tour riding or riding two up".  Is this just marketing mumbo jumbo?  I don't fancy too many people going down to the 180 on the C14, more people going up to the 190/55.  I'm just trying to figure out if I will get extended mileage, better wet grip, or just "piece of mind" from the 'B' tire.  Any feedback or comments are appreciated!

On the Pirelli Angel GT they call it a 'A' spec for the higher load rating. I did get mine in the A spec. Since I haven't had the tire very long I can't report on the mileage. I can say that I'm loving this tire so far! I had a PR2 rear previously, still have one on the front.   

I understand the B tire has a third belt wrapped around the carcas... simply to resist the 'squat' of a radial tires sidewall. I have heard repeatedly that it will NOT get higher mileage (same rubber in the tread). It will NOT grip differently (just great in the wet or dry). And the 'piece of mind' is knowing that you (might) overload your bike, but the tires sidewall is stiffer to carry that extra weight properly (as if you carried less weight on a standard tire).

All I know from experience is I weigh 180 and carry very little 'extra' stuff, so I buy the standard tire.  It works great, lasts a long time, and I have lots of piece of mind.   YMMV