What the heck are you going to do on a Galaxy Note? Are you serving the same site on a Wildfire S as you are serving a Galaxy Nexus?
9 times out of 10, whenever a webdev tries to be "smart" and serves up a mobile version of a website, I don't want it because it's a crippled, badly working knockoff of the real thing. Chrome and Firefox on Android are real browsers and can display the full site, so stop feeding them this crap.
I heard there's a room in hell where you are forced to use various Android browsers on various mobile devices all day.
For smartphone: 15903 bytes
For old phones (mostly text): 2369 bytes
Server-side device detection does make a difference here, and in other footprints (initial external resources, backend services) as well.
I don't think UA sniffing tells you what connection I am on, right?
Until the code becomes more open this is a step backwards.