After months of waiting I managed to get my connection installed with XLN. Just happens to be in the same location as another existing connection from Plusnet.
Both using the same draytek router and set up the same. Link speeds are roughly identical, XLN being slightly better.
However real world Plusnet get me 72/19mb, TalkTalk 50/12mb. Jitter is even worse, nice smotth 30ish ms ping from Plusnet, anything from 13ms to 1000ms with TalkTalk. This makes it unusable. My VOIP, VPN, video streaming all drop regularly.
Any ideas how I can get out of the contract as they say there isnt a fault, live with it! Trying the TBB monitors below to see if the results are the same.