I'm going to go against the popular grain in this thread.....I've been diving with a clear skirt for the past 14 years and prefer the clear over the black, mostly because that's what I'm used to. Even though I'm not claustrophobic, the clear gives me more of a feeling of "openness." Like most clear-skirted masks, the clear is more of an opaque (cloudy-clear), but I can still make out objects and light signals with my peripheral vision, which has been very helpful many times with buddies and students, and with spotting large animals as they got nearer.
I never noticed the glare at shallow depths with my clear skirt until I read about it here on ScubaBoard, so now I notice it once in a while if my head is tilted at certain angles. When I take underwater digital pictures, I can focus on the screen because I'm used to my mask. I can see how a black skirt would help to focus on the camera screen and eliminate some glare, but for me it's not a big deal.
My favorite mask is the Atomic Aquatics medium frameless with clear skirt. Long story short....you get used to whatever mask that fits you the best and you use the most. Fit and comfort is much more important than looks for those that think black skirts look "cool."
Hope this helps!