Hi David, Yes my apologies kind of forgot to add a reason to that question, your probably the best person to ask this... did you notice any improvements to service when your where switched to Zen's backhaul? and do you find any issues at peaks times with Zen's backhaul? and finally what region of the UK are you based in.

At first, the quality of service was slightly worse over Zen backhaul, as there were brief periods of increased jitter. This seemed to be initial teething issues whilst the Zen network engineers tuned the network parameters. These issues disappeared after a few weeks and have not returned.
The big bonus came some time after I switched to Zen backhaul, as I moved from connecting to the Manchester gateways to connecting to the London gateways. This improved my latency to London based servers, as I'm 40 miles roughly north of London.
I posted about that at the time.
I'm not seeing any visible contention on the Zen network at any time of day.
I'll PM you an accurate location.