I have a real problem with gloves that change my dexterity. I absolutely could not use the lobster gloves, as they just felt so weird to me. I have a pair of PI Amphibs that I've worn in the 30s, but I feel they compromise my shifting, get stuck in the shifter. And, I think they are too small. They were fine for using trigger shifters, though.
I've settled on using Ibex liners under a pair of Terry light weight vented full fingered gloves. At this time of year, or below 40 or so, I put a chemical warmer in between, on the top of my hands. Sometimes my hands still feel too cool. But, most of the time, they warm up after 5-6 miles. Now that I seem to be pushing my limit for my low temperature limit, I wish I could wear something else. I am just so uncoordinated, that the slightest change in anything throws me off. I'd like to try the Amphibs today (high of 28), but when I tried them on, they felt way too tight and thick. When I first started riding I actually bought gloves in x-small, then went up to small, and now I wear mediums. I think the Amphibs are smalls.