Warm and comfortable, prefer it to the waffle style.

I often thought, "if only there was a base layer that was a thermal tank..." and then I saw this one! FYI I'm a female size medium and I ordered a (men's) small and it fits great. Keeps my core warm and lets my pits sweat. So, yeah.

Warm enough to wear throughout the ride but not too warm that you want to take it off.