I have been looking into ISP alternatives myself of late and it seems A&A and Zen are the best alternatives to Uno, but they are as pricey or even more costly than the Uno option.
If you never really have any issues with sync rates, don't want to use your own equipment etc I would be tempted by BT, only if you can claw a good deal out of them. but most of them should be fine in this case. If you often have problems with your line I would stay well away from those with bad CS.
Before I signed my contract with BT years ago I was tempted by Plusnet because of their reviews, CS and price, but I had never really heard of them up until that point and I thought their pricing system was too good to be true at the time. Since then though the reviews have slipped a bit all citing the same things about payments and CS going downhill.
If I switch I might just go to A&A, hopefully they can sort my line out. People reckon it's crosstalk which they are most likely right but there are also a few niggling problems on the line because my sync rates are 17Mbps lower than the maximum data rate, noise margin is 10db and my HUB is prone to going down for a few minutes resetting every 1-14 days.