both...i got the burton glove / mitten, where the inside is a glove so you can still strap in, the shell is a mitten that's waterproof. I prefer mittens as my fingers / hands get cold pretty easily, so being able to move them around helps. You can also hold handwarmers inside most mittens
Gloves. You need to be able to articulate your fingers while riding.
i completely disagree, most of the time people end up pulling a glove off to do things like change the songs on an i pod and what not, i ride with mittens and have never ever had a problem strapping in. My mittens are also super sick because i can unzip the top part around the knuckles of my hand and stick my fingers out of it if i need to do something with my fingers. its the best of both worlds, but dont tell me your supercapable of changing songs and shit on your ipod with gloves on anyways. Mittens are warmer.
mittens ftw especially if you can find some like mine but iv never seen another pair.