I've been using Metzeler Me33/Me99, now the Lasertec series tires, and I am quite satisfied with the performance of them, I've been using them since 1987 .
Don't get a lot of wet weather here in Phoenix, but the few 'gully washers' I've been in, the tires performed quite well .
I haven't noticed rain grooves 'upsetting ' the handling any more than I experience with any of my 4 wheelers .
I get about 8-10,000 miles on a rear, and 11-13,000 on a front tire .
Cost is a bit higher than other tires, last set cost around $350 for tires, tubes, sales tax, mounting and balancing .
I only put at best, 2,500-3,000 miles a year on the R65, so if you put a lot of miles on your bike, this may not be the best choice cost wise .
I have seen reports of 'cupping' of the tread, I haven't experienced it so far .
I've been getting my tires from Southwest Mototires, in Tucson, purchase 2 tires, and shipping is free .
Since they moved to the Tucson location, I take the wheels to them, and have them do the mounting and balancing, $20 per wheel/tire assembly .
http://www.swmototires.com/