The favourite Openreach modem is probably the HG612 because it can be unlocked and provide stats. The poor ECI gets dumped on eBay because it's locked down and offers nothing to the customer beyond switching it on or off. Good news is you can now install OpenWrt on your ECI, if you are willing to do a little bit of soldering(very little) - it's all explained over at Kitz forum in
this thread.