I've owned professional-grade masks for years. Even when I was a kid, I was spending the dough to get the good stuff to play with in the pool.
My last mask was a SeaQuest Ventura. I loved it. It had a clear skirt and a green frame to match my other electriclimabean green stuff. Fit great, low volume.
Well, one very sad night it was stolen.
So when I started taking my class, I decided to buy what was quick and available... A cheapo mask by U.S. Divers. It had a single lens, blue frame, and clear skirt.
When I got my OW, I decided that I was going to really spend some time underwater. So I gave myself an allowance of $150, and said that I could buy any mask I wanted, pretty much.
After trying on a hundred different masks and reading every review I could get my hands on, I found that by far and away, there were three masks that fit me best. In order, they would be the Scubapro Fino, The Oceanic Lite Vision (the smaller one), and the Cressi Horizon/Big Eyes (the difference is the extended lens on the side.) All of these fit great... However, the Scubapro Fino was invisible on my face, and didn't have batteries in it, which was sort of gimmicky. The Cressi masks certainly were awesome, especially in their ability to look down... But one of the reasons for that was a lens that was 18 degrees off vertical, meaning that it was bending the light underwater. Sure, you get used to it pretty quickly, but I wasn't really interested in using anything that wasn't showing me the "real picture."
Personally, I find that the best masks are those which are lowest volume, and as simple as possible. I prefer one lens over two because when you spit in one lens to defog it, you can tilt the mask and use the rest of the spit rather than having to spit twice. No big deal either way, really. But most super-low volume masks have two lenses, and I don't really notice a difference between the two when they're on my face. The Fino is a two-lens mask, and ultra low volume, preventing buoyancy problems, allowing me to have the most periferal vision, and distorting the size/distance of things the least.
This simple mask was only about $60... So I bought them both... The clear skirt and the black skirt.
I can't say enough about this mask in terms of fit and quality. I'm very happy with both of them.
I find that the clear skirt "ghosts" at the surface. Light comes in through the sides (through the clear silicone) and reflects on the inside of the glass. It's not bad, since this mask is such low volume, but it's there a little. It's noticable between the two masks. Doesn't bother me too much, but it's there. I find that because of this, there is some truth to the idea that black-skirted masks allow for clearer vision. Of course, this is only an issue at the surface or in shallow water. Another thing that I noticed, however, that nobody's mentioned here, is the "bubbles" problem. Exhaling through a reg obviously produces bubbles, and they go somewhere... Typically just to the left and right of your mask. I find the bubbles a bit distracting while scuba diving, especially when I'm in dark water (like at night) and I have a light. The bubbles shimmer, and in my peripheral vision. Again, it's not bad, but I do find it slightly annoying.
Lastly, I find that as a whole, silicone does yellow over the years. It doesn't yellow as fast if you keep the mask in a case, but it still ages and yellows over time. The black silicone doesn't show the yellowing as bad as the clear.
So which do I use? The black skirted Fino. I like it better because there's no "ghosting" on the inside of my lenses, it doesn't show wear as bad, and while scuba diving, it doesn't allow for the distraction of your exhaled bubbles.
...But I can see the legitimate argument that with the clear skirts, there is a little more allowance for peripheral vision. I minimized it's effect by getting a mask that fits as close to my face as possible. There's still a difference, though.
I think I might be more inclined to use a clear-skirted mask when snorkeling, since you're not exhaling bubbles like you do while scuba diving. 'Course, snorkeling is done on clear, sunny days in good vis waters, and "ghosting" would be really bad, so it'd be up in the air for me on which I would choose.