Well I have been playing BF3 since I bought it, using money I earned from selling shit on TB xD. And since then, apart from playing awesome SP games ( Skyrim, Max Payne 3, etc) I have been playing a few other online games too ( Path of Exile - very awesome but there's a wipeout at almost all major patches so until the Open Beta I'll take a break from it - and Pokemon World Online - YES I LIKE POKEMON SINCE I WAS A KID).
Well I did try out Arma 2 with snake and bojan for a few days but for some reason it can't keep me entertained. The whole game is very weird for me, with no clear objective, unlocks don't feel rewarding, and there's no destruction engine like in BF3. Arma 3 did look extremely awesome from the trailer, but if it will be the same as Arma 2 I will stick to BF3.
Also you don't need 10 mb/s dl speed to play BF3. There are servers from all over the world and from all countries. If your ping is under 100 ms then you should be good to go. BF3 is really worth it, I will even buy premium out of my own money after my finals are over.
How about you William?