These bib tights are very comfortable - the "thermoflex" fleeced interior adds warmth in addition to being extremely soft and plush. Layering them with another pair of bib tights, I've biked well below freezing with no difficulty.
The no-chamois version is versatile - aside from cycling, they work great as running tights, or as a layer for any kind of winter activity. I wore them as long johns on a camping trip once.
As with most everything Castelli, you need to size up. I'm on the smaller side of medium by their size chart. When I tried on a medium at a local MEC, I was able to squeeze into them, but they were pretty constricting, and I was barely able to close the ankle zippers over my socks. Even the large is fairly snug compared to other gear I own, but still comfortable.
I do have to partially agree with one of the reviewers below - the stripey pattern, made with several separate small panels sewn together, is unnecessary. Castelli's products are great in performance, but I find their looks to be pretty ostentatious and this one takes the cake on that front. The stripe panels, the two red logos on the knees, "Castelli" in giant letters up each leg... I don't need to draw that much attention.
Performance-wise, a great product, and a real steal at the sale price. Highly recommended.