Oh god if three's service is as bad in the uk as it is here in Ireland (I recently swapped from Three to O2 broadband) then no saving is worth that hassle
My Three broadband expires at the end of the week. My download speed last night was 86.5kbps down and 60kbps up... compared to O2 which was 1.68mbps down and 164kbps up.
Even at off peak times with three we only get 500kbps.
And I'm flat bang centre of HDSPA signal reception.... They are just rubbish here.