said by Scycotic:
The WRT160N, E1000 and E1200 are 300Gbps 2.4GHz N w/ Fast Ethernet
The WRT310N is 300Gbps 2.4GHz N w/ Gigabit
The WRT320N(essentially the E2000) is 300Gbps selective dual-band N w/ Gigabit
The E4200 and RT-N66 are simultaneous dual-band N w/ Gigabit
In most cases, it is a good idea to limit your wireless choice to 20MHz bandwidth. This is because wireless spectrum in the 2.4GHz band is already way over used, and choosing to widen your footprint opens you up to twice as much potential interference. It also adds interference for your neighbours. So, 300Mbps (not Gbps) choices are generally a bad idea, even if they are available.
Now if you live in a very isolated area, where you can only see one or two weak wireless networks, or none at all, of course go nuts and do whatever you can for better speeds. In cities, you aren't going to see that.--