I just used the UA Cold Gear shirt last week during a round in south/central NJ. I teed off at 7:10 AM on Sunday with 40-50 degree temps. The shirt was sweet!! I wore it under my UA golf shirt (coincidence) and shorts.
The shirt didn't restrict my movement at all and was extremely comfortable and warm. IIRC, the temps rose to 50-60 during the last few holes of the round and I did find myself pulling up the sleeves to give my forearms more cool air.
One downside, I happen to wear the only synthetic material golf shirt I own over the cold gear and had a heck of a time keeping my shirt tucked into my shorts. I assume that since both shirts had some combination of spandex/nylon/cotton/poly? there was no friction to keep the golf shirt tucked.
Anyway, I love the shirt and will probably buy one more. Since I HATE wearing jackets during golf, I'm guessing I can wear the cold gear under a golf shirt into 30 degree temps. There are probably cheaper alternatives but since this worked for me I will not experiment.