Mi-Fi options

This is my first post since joining so I hope I am in the right area!
I am currently with BT receiving around 4-5 mbs which is a bit limiting between myself (connected PC) and my partners wireless connected laptop some 15 ft away. There is no prospect of changing to Virgin media as we live in an apartment block and Infinity looks like being years away.
My question is should I get an unlocked mobile wireless device and if so can anyone suggest which one to go for?
Mnay thanks in advance

Have a read of this thread as a starter for 10 - might give you some ideas and help to further formulate any questions that aren't answered by it.