I agree, these things are great, a lot of the pedestrian signals around here are being changed to them. I live a bit north of Ft Myers, in Port Charlotte, and some intersections around here have them, where as further north in Sarasota county, almost all major intersections along 41 have them, useful since very often work takes me south or north along 41 primarily.
About short yellow lights, I guess it's about where you are from, a few years back a guy I knew from NH commented about how the yellow lights lasted longer here.
The cameras are also becoming more common around here, though you still see many people run red lights, most often following the car's bumper in front of them, or snaking behind cars in left hand turns.