Check out
http://bbs.adslguide.org.uk - note the plusnet and Bulldog forums especially as they are two ISPs mentioned here.
The grass is certainly not always greener. Plus are having some lovely arguments in their forums about download quotas, ever since someone realised they keep maxing out, adding 155Mbit, maxing out again within literally a few days, adding 155Mbit, maxing out.
When you have in their own figures less than 1000 users using 1.8 million quid a year's worth of capacity from BT alone, not including transit and all other costs not really that surprising a congestion free service isn't viable for them. Plusnet lottery as to whether you get congestion or not.
EDIT: On the other side of the coin I quite agree that more upload is required. To be honest 2Mbit with 256k is too asymettrical for my taste, however that's the standard that BT have set.
By 3Mbit IMHO upload should really be 384 at least. Though I'm going by Canada where even 1.5Mbit DSL comes with a 640k upload
EDIT AGAIN: Oh by the way, talking of Bulldog, they may put their own equipment in the exchanges, it's still BT's phone line connecting you to it
