Pros: Warm, dry, long gauntlet, wrist strap, membrane in outer surface of the shell, fleece in liner and shell
Cons: Cost, bulk
I've always suffered from cold hands; on really cold days I'd be on the lift pulling my thumbs into the palm of my mittens to hold onto two heat packs while I clenched and unclenched my fingers. I'd never spent more than about $70 on mittens, and I finally decided to buy something that would actually work.
I'd whittled the list down to the Arcteryx Alpha, the Mountain Hardware Medusa, and these. The MH's weren't in the store, and I hate buying things I haven't handled. The Arcteryx felt a bit stiff in the thumb, but really I didn't like the short gauntlet. So I got the OR Alti.
I've had them out eight or ten days and so far I'm really impressed. The first day was 20F with 10 mph wind, and my hands were sweating (I was working pretty hard at a toboggan handling clinic). No problem, when it's warm I swap out the liners for some thinner ones.
Yesterday it was 30F, 20 mph winds gusting to 35, and when my hands got cold I got out the liners it came with and in five minutes my hands were warm. That's never happened to me before. So I went inside and held them under a faucet for a couple of minutes, went back out for an hour and was perfectly comfortable.
Yeah, they were really expensive, but you pay for what you get. Yeah, they're bulky but that's unavoidable unless you can violate the laws of physics.
I recommend them highly.