I’m being pedantic, but that’s not really Zen, it’s the BT Openreach backend which has really great stability and latencies. I tracked my BT Openreach connection for many years and I never got more than a few ms of jitter, really amazing. However the speeds are not great (70/20), and the coverage is also fairly poor - I'm in a dead zone right now between two local exchanges. So unfortunately I'm forced to use Virgin, which has gotta be the worst ISP in the history of the world (and I have had Comcast!). Terrible network and terrible customer service - I don't know how this company exists.