It appears that Danley was wearing a Wilson West Vest Dyna-Lite Umpire Mask.
Later in the year he switched to a hockey helmet.
It really makes you stop and think, doesn't it? I could debate the pros and cons of traditional vs hockey masks, but Mr. Danley's choice speaks volumes. The hockey helmet offer better protection, period.
So what is the difference? Danley's traditional mask weighs around one pound and the typical hockey helmet weighs about twice that, but the weight is more evenly distributed.
Considering that you should only wear your mask when you are calling balls and strikes (during the pitch), the added weight does not seem all that big of a deal. The price is not all that different between the two styles. There is even a lively debate here: http://forum.officiating.com/baseball/49344-numbers.html
One last consideration. I expect my mask to last a few seasons. I take care of my equipment, so five is generally the number that I have in mind. The thing is, I go through about three plate hats each season. Even with washing and storing in a hat cage, my hats fade and look poor after a time and require replacement. At about $15 each, that adds up to $45 a year times 5 years, or an EXTRA $225. Also, I like the idea of whatever extra breeze I can get through my hair (what little I have) during the game. When I consider all of the above, I think I have talked myself into a hockey helmet.