I had the CPW LLU in mind.
While often used by TalkTalk, where many users complain of its poor customer service and its traffic shaping, other ISP's using the CPW LLU may well offer much better services for it.
IDNet itself may have good customer service, and it doesn't use traffic management, yet IDNet is also quite expensive because it only uses the BT infrastructure. IDNet doesn't yet offer LLU services. When something goes wrong with the BT network, IDNet may not always be able to get BT to sort things out.
Hence my advice to the OP is to also consider some of the better ISPs using the CPW LLU instead of BT network.