You might try TCP optimizer on all your PCs and lappies.
http://www.speedguide.net/downloads.php I got an immediate improvement on my N-router wireless connection to laptops. Beware though. The age and spec of your laptop will affect download speeds.
Don't expect anything like 50mb anyway. To get over 30mb would be outstanding!
I found it better to get some ex BTVision Comtrend powerline adaptors off eBay (£30 - £40 a pair) I have set the whole house running off of these to serve games systems and the media PC etc. I'm getting 40mb+ through those. It is really easy to get different pairs of Comtrends to talk to each other.