I've read most of the responses so far, now my 2 cents.
I don't have the RWHP most of you have but, I started using Nitto DRs for road course and drag strip before they came out with the R2s. I still use them for street use. I have nor ever had any problems in the rain, they grip better than any street tire on the track in the rain.
What they don't like is what any wide performance tire doesn't like. Standing water.
Standing water will make any tire hydroplane, and really when they wear halfway down.
Bottom line is be careful and you will have no problems.
I don't have the RWHP most of you have but, I started using Nitto DRs for road course and drag strip before they came out with the R2s. I still use them for street use. I have nor ever had any problems in the rain, they grip better than any street tire on the track in the rain.
What they don't like is what any wide performance tire doesn't like. Standing water.
Standing water will make any tire hydroplane, and really when they wear halfway down.
Bottom line is be careful and you will have no problems.