I wear these when I am pretending to be a roadie, or I'm racing. Just so I don't look like a complete beginner. I like them. They fit snug and best of all, they don't get hot. I wore them in a 94 mile ride in over 100 degree weather over the weekend, and never got uncomfortable.
I bought these to do a Grand Canyon R2R2R. I tried them out a couple of times in training first, but was still wary of getting sick of the taste during the run. So wary that I took another bottle of clear water in case I needed to wash my mouth out. I carried that bottle of clear water the whole way without drinking it. I never got sick of the Nuun taste.