What are the differences between gloves and track mitts? (other than the obvious lack of covered fingers)
I've used both fingerless track mits and full-fingered gloves. I've found the main difference comes from what you intend to do, and how long you want to do it.
Comfort: I found the fingerless mitts a lot more comfortable, making them great for longer rides. This would be especially important if you're looking at touring through a residential area, taking the long commute to work, or otherwise staying on roads. Once the temperatures start to drop however, the comfort of the fingerless mitts is defeated by the cold, so it's a good plan to switch up during these conditions.
Protection: When just biking around the city, chances are if there's an accident, having your palms protected by the fingerless mitts is enough. With smooth ashpalt beneath you, your fingers aren't going to do much in assist in breaking your fall. When mountain biking however, every bit of extra protection helps. The full-fingered gloves provide enough protection to keep your hands working well after most collisions, flips, slides, and scrapes. They won't do much to prevent a full-on break, but stopping a lot of scrapes and bruises can be a lifesaver, especially if you use those fingers for your living.
Sweat: Both gloves do provide some wicking. The long-fingered gloves pull the sweat from the entire hand, whereas the fingerless only grab the palm. This can make a huge difference on exhausting rides as the grips on the bicycle get covered in sweat.
Grip: Although both types of gloves provide additional grips via the palm, only the long-fingered gloves provide additional grip in the fingers. This can provide a lot of advantages if you're worried about aging handlebar grips, or are forced to discard the grips after an accident and cycle back to town using only the raw handlebars.
Tactile Sensation: Here is where the fingerless gloves shine. Because they're still fully exposed, you can feel everythign with your fingers as per normal. This means you can quickly pull over to check your cell phone, fiddle with your bike computer, or whatever else you may need to do that requires fine motor skills in the middle of your trip.
Although I've come to miss my tactile sensation, I've found the full-fingered gloves to be more useful on the whole and have opted to use them for the majority of my cycling trips.
In my opinion, track mitts have a much better feel on the palm, even with a comparatively stiffer material.
I do have winter gloves that are made specifically for bicycling, and they do a good job of warming the hand. But the more elastic material on the palm shifts all over the place on long ride, despite the seemingly snug fit of the gloves.
Btw, I once had some particularly comfortable track mitts that completely failed in the protection department, on a crash the palm material just peeled away from the palm. Go leather, I say.
The difference between full-fingered gloves and track mitts, besides for the obvious fingerless part, is that with the mitts you have the added advantage of material that flicks sweat off your hands giving you a more comfortable ride. Additionally for both, different gloves come with padding or gel that takes some of the pressure off of your hands to give you a more comfortable ride.
Personally I would not ride without them. They make you able to ride long distances because they take one more thing off of your mind while riding.