If 70% of the population (maybe it's less or maybe it's more, but I heard that ballpark figure somewhere before), have access to at least one LLU provider, I struggle to see how smaller IPStream suppliers cope. I mean, O2 for example have superior usage limits, for the moment - superior speeds (this is whilst LLU is in its prime - it could all go Peter Tong like it did for some BTwholesale suppliers before when CBC charging was introduced at the wholesale level) - and keen prices.
Plusnet were great for me for over 2 years, but finances dictated a move - and I haven't looked back. I have a Sky connection at home, and an O2 connection at my house here at university and they're both brilliant (Sky one may have the edge) and very very good value.
matt