My hands tend to get cold rather easily. I've tried just about every possilbe comination and type of liner glove, fleece glove, windblock glove and insulated mitt, overmitt, etc. I've tried vapor barrier gloves. I've even gone so far as to wear different glove/mitten set ups on each hand all day so I can compare different systems. It wasn't until last year that I found a combination I really liked.
Hands down, the liner glove that works best for me is the Mountain Hardwear Tempest SL
glove. I don't know if it was intended as a liner glove, but I REALLY like it for this purpose. I bought the glove just large enough so that a really thin poly glove will fit underneath without constricting circulation. I'll wear the thin poly glove underneath the Tempest SL on really cold winter days. If my hands start to get cold, I'll wear insulated mitts over the liner gloves. The Tempest SL does a great job of keeping moisture out, breathes well so the hands don't get too sweaty, provides good wind resistance, and offers great dexterity. I don't have to take the gloves off to ties shoes, put on crampons, etc. The glove worked so well that I didn't have to change my liner gloves once all last winter, although I did take them off between hikes while at home.
I use Black Diamond Mercury Mitts as my insulated overmitt. I like these a lot too. First, the mitt has a removable liner that is Primaloft on the backside of the palm and fleece on the inside of the palm. The fleece on the inside of the palm is a nice touch because Primaloft will compress under preasure, lose its loft, and hence its ability to insulate is reduced. I use poles in the winter, so this is important. Unlike some removable mitts, these mitts really stay in place. I've found that with some mitts, everytime I pull my hand out, the removable liner mitt comes out with it. There are warmer mitts (like Marmot Expedition and OR Alti Mitts), but these have a more delicate face fabric and don't stand up to scrub brush so well. I personally owned the Marmot Mitts, and although they were exceptionally warm, the ripped too easy. I believe they may have been redesigned though. The Mercury Mitts have a tough face fabric that stands up well to scrub brush. The leather palm is not the norm these days, but I believe it insulates better than the plastic palm and offers comparable water repellency when treated with a DWR product (preferably a rub in type ointment/oil). The price on the Black Diamond Mercury Mitts is another reason to like these mitts.
John