I purchased the WarmSkin Skinny Base Layer Thermals YEARS ago for my husband, and as we both aged and gained weight, his became mine and I just purchased another set for him. The quality hasn't changed in all these years. Great insulation without being too bulky - we are able to ride very comfortably in 50/60 degree weather with these under over our shirt with a good coat/jacket. Note that this indicates the old set - at least 15 years old, maybe older - has held up - I am still wearing them. Worth the price - I HIGHLY recommend.
I've had this shirt for years and it's ridiculously warm. I love that the sleeves are actually plenty long and the body is also long enough to stay tucked in. I mostly use it for snowmobiling, but only on the coldest days because it's nearly too warm if you're working. I will wear it for work (construction), but it's either gotta be real cold or you can't hardly wear a jacket. Awesome shirt