Thanks for the posting and thanks to others who have made comments both + and -.
Have had some changes made to my existing line and wanted to see how it stabilised before jumping ship from existing provider. As per my original post, with a move to Zen, I can save money, move from ADSL2+ to VDSL and get a new router similar to the four year old Fritzbox I already use.
As long as the line is stable as reported here my requirements are very modest; no gaming just occasional TV and big W10 updates - I won't get more than 20Mbps out in the sticks.
As I use a Fritzbox and run both IPv4 and IPv6 BQMs I was interested in the ping loss discussion. Interestingly, the 4 graph shows loss even over-night when there is no other traffic; the 6 graph is clean. [That is not Zen! but it is a Fritzbox (7390)]