I have the Terry gloves for temps down to about 50, 48. Sometimes, I wear thin liners from EMS under them. I have a pair of PI gloves that are heavier for temps down to 35 or so. They feel a little awkward shifting my road bike, so I have to be more "aware." They are fine for the mtb, though. I bought Craft lobster gloves last year. I really hate them. They fit well and keep me warm, but I just don't like the feeling of having my fingers separated. I can't reach the shifters as well.
An expensive mistake, so what i ended up doing on a couple of cold days was to put chemical warmers between the liners and my lighter weight Terry gloves. Perfect for mtb rides in the 20s.