Eircom started rolling out vectoring in Ireland last spring.
In a recent publication by the Irish government (showing consultation responses to their equivalent of BDUK) , we get to see a graph of speed vs distance. In the published document, see page 97.
How much does this apply to the prospects of vectoring in the UK?
Ireland tends to use 0.5mm copper like us, are using Huawei DSLAMs, and their equivalent of the ANFP puts the same power masking requirements that we have.
However, they run their DSLAMs with a 9dB target margin. If they used 6 dB margins, speeds could be 11 Mbps higher on the left half of the graph, with the increase dropping down to an extra 2 Mbps at the longer distances.
Here's a copy of the graph in that document, with an extra line showing theoretical behaviour with a 6dB margin.
I don't see any other significant differences in their line plant. As ever, words of caution need to be added for aluminium lines.