Year drop-downs are annoying for things like DOB because there are 100 choices to scroll through. Reminds me of my Humana insurance app where some questions had drop-downs of literally 1,000 values, so I'd swipe and swipe for several minutes, but if I swiped outside the box by a little bit, it would collapse and I'd have to start over. Eventually found that I could select a part-way value and then start swiping again, and if it collapsed I would at least go back to the part-way value.
So, typing in Y/M/D is better in most cases for DOB than drop downs, unless maybe it's dropdowns for [YYY][Y], then [MM] and [DD]? Or how about start with "How old are you" and then get me most of the way there on the picker? :-)
