I use Nanoflex on damp days or when there is rain in the forecast. I think they have a little less stretch to them than the Thermoflex, but they are warmer and provide some nice protection from the wet. 6'-1160 and medium fits me well. They do stay in place nicely despite a little less flex. i may pull them up once or twice on a long rides if i make a stop, whereas the Thermoflex don't budge on me. Or i can just ride through and not worry about them. seem well made, only been through a few washes but no signs of any wear.