I have a pair of each. I wore the unlined ones yesterday for a 200K. It was in the high 50s when I started the ride and climbed into the low seventies.
I wear the fleece lined ones for days that are going to stay in the low sixties.
If the day is staying below 55 or so, I want to be in tights. I have two different weights of those as well - a fleece lined pair and a heavier pair with wind resistance built into the front. The lighter weight ones have a chamois, the heavier pair doesn't so I wear shorts under those.
I also have a pair of rain pants that I will wear over the lighter tights. When combined with the heavier pair it makes me too hot.
Veronica

