Things may have changed since then (i.e. newer firmware)
I run two connections with Zen, neither of which uses the Openreach modem. One uses a Cisco 887VA and the other a Draytek 2850.
The Draytek is on a good line and is currently synced at;
Actual Data Rate 19999kbps up 59614kbps down
Attainable Rate 21045kbps up 59614kbps down
Firmware is 3.6.2_2471201
there are no issues with the line dropping out even with high data loads.
The Cisco is on a poor line but still syncs as well as the Openreach modem.
Edited by caffn8me (Mon 14-Jan-13 01:07:43)