Moved my home account from PN last year, after 9 years, due tho ever increasing restrictions on usage and moved my office account after the email problems in April/May.
I regret not moving sooner. Except for a few service problems in the last 10 days which have been promptly dealt with I haven't needed to keep an eye on service status. Unlike PN no empty promises of fixing things and then waiting weeks for improvements.
Zen have no restrictions on how you use your account and an uncontended internal network. P2P works fine, as does everything else. Zen aren't as slick with their portal as PN. The default email address is naff,
[email protected] where X is a digit. I haven't tried aliases for email so don't know what you can do to change this, I have my own mailserver set up while still with PN to get round their problems so no longer rely on my ISP for email.
I've rung CS 2 or 3 times due to BT related issues, no duff ticket system to get in the way of communication. Each time CS were clear about the issue, unlike PN where CS just tried to blame my set up and get me off the phone.