Wireless performance is pretty immaterial unless you are connecting to a high speed LAN (Local Area Network). If you are using wireless to connect to broadband then it is unlikely that the Broadband circuit will be running at more than 2Mb - possibly 8Mb if you live in a telephone exchange - therefore the best performance you will ever get is limited by the broadband speed, not the wireless speed.
There are three common standards for wireless, namely IEEE802.11b,g and a.
.11b is the slowest and offers a maximum of 11Mbps - so, in theory, more than enough for broadband internet use.
.11g is similar to .11b and operates in the 2.4GHz band and offers a maximum speed of 54Mbps. Note that speeds are theoretical and depend on how far you are from the wireless device and how much RF interference there is around.
.11a operates in the 5GHz spectrum and is therefore less likely to be affected by interference. It is also less common and more expensive than.11b or .11g. .11a offers speeds of up to 54Mbps.
A new emerging standard .11n is available on some devices - mainly Apple MAC's - and can run as fast as 300Mbps - but when your broadband is only running at 2Mbps, what's the point.
I suggest you go for a cheap .11b device (about a fiver on ebay) or buy a .11g for multiple users. Note that even on a .11g device, if a .11b user connects to it then all devices connected to that wireless access point will revert to .11b speeds unless the AP is dual radio (highly unlikely under £200).
Clear as mud??
