I didn't read the thread, so forgive me if I've missed info or if what I'm saying has been covered.
I used to have Vox Fat Pipe at a really cheap price, 150 odd for 400GB a month (capped account) it initially started out as a 200GB account, also capped.
The capped account was of my choice. That way I could hold them accountable for shite speeds. Then they eventually had the unused data rollover for 6 months or something. I was eventually stuck with 2TB of unused data. Then I moved and no ADSL available.
Never had speed issues. Signed up for Afrihost free 1GB account to compare and Vox beat them.
VOX is a great company when it comes to ADSL in my opinion.