Just purchased my second pair to have another pair. Use so far has been completely on a trainer, riding up to 2 hours so far they are very comfortable. No movement, chaffing or soreness so far. Breathability difficult to determine without air flow but I plan to use these on extended outdoor rides as well. Solid.
Excellent Bike Shorts - Pros- These shorts are the most comfortable short you can buy. Great if you are out for a short ride, but where they really shine is on longer days in the saddle when your are touring or you are out for another century ride. Cons - They are pricey.
I now have two of these because of their versatility. It can be worn on or off the bike and doesn't scream bike wear so it's great for traveling. It kept me warm down to about 40 degrees. I can go either small or medium in this brand. I bought a medium so I'd have a little extra room to layer it and use as street wear.