Having had sub 0.5Mb/s speeds for 5 years and with BT recently telling me that they can no longer provide a service (multiple probs since move to them in February - Long line, 'final third', Market 1 etc) I have moved to 3G.
With a Huawei Omnidirectional antenna, 3 premium dongle and a TP-Link router I'm getting 2.5Mb/s.
OK so its about 1/3rd of the alleged national ADSL speed and its a bit up and down speed wise at times but its actually usable.
I am not a big downloader so the 15Gb cap per month is not an issue but its really great to be able to watch something stream without waiting 10 minutes for it to buffer and I can download programme updates in an hour or so rather than overnight..
At this time I could see the advantage of say 10Mb/s but I'm not sure what I would do with 50 or 100 - I guess there are many who do need this - families and serial torrent users mainly I guess!!