Something else to think about. You can have 300 mbps, but if your ISP has a download speed of 10 mbps, that will be the limiting factor. Of course you can transfer pc to pc wirelessly.
Thank you...was waiting for someone to give the most important bit of information.
The speeds you are worrying about are far more than what your actual connection to the internet is. Any wireless adapter above B will be more than capable of handling whatever your ISP brings to your house.
That's like spending extra money to make sure a car goes from 150 mph to 200 mph, even though speed limits may be 55-65 mph.