i own both and also got the 1200 first because i love the oled screen. it is pretty annoying to use because of how friggin slow it is but the sound quality is outstanding and i don't need a lot of space on the go. i use the hd3 for when i'm going to be stationary, say hooked upto a speaker at work or at a party and such... i like the looks of the hd3 more, esp with its metal case instead of the glossy plastic but the 1200 size is more comfortable. i think the a1200 sounds a little more crisp, but i definately prefer the older hd3 in overall usage so i'll probably end up selling the a1200 or trade for an hd1 to keep in the car.
