with all other users on your mast. So in that sense it is like the Cable market where you share your connection, with the appropriate speed drops at heavy times.
Whilst it is true that bandwidth is shared somewhat, the bottleneck isn't the air interface as you suggest but in fact the backhaul to the base station!
It's easy to get over 5Mbit sustained download speed using torrents with a 7.2Mbit data card in the city. (Telstra Next G - Australia). In rural (i.e. country) areas 2Mbit is doable.