I tried the Latest release candidate R23RC2 and that was more stable but still no increase in throughput, I put my old 2016 build ECI modem back on and my latency (QoS is off on the router) went from 200-300ms UL on the Draytec to 30ms on the ECI, download is about the same at 38ms Idle at 18ms and on TBB and I get a B down and b Up or a A down and B up on bufferbloat compared with A and F with the Draytec, with spikes up to 314ms and sometimes erroneous downloads of 1GB peaks which would be a miracle.
The new beta firmware gives some of the stats now but still no errors but does show the cab you are on, I am on a ECI. After a month of this modem I have decided to return the 166 (I have a week) its just not worth the effort to keep playing with it and watch my downloads actually become corrupt due to packet loss I imagine. Also I won't buy a Vigor 130 as I believe its the same chipset as in the last ECI v2 Openreach modems anyway and they run just fine on my cab.
My ECI modem runs cooler, syncs better and even though I am still interleaved I did gain back 3 Mbps straight away, so hopefully I will get the whole 10Mbps back in about a week or so. The 166 needs alot more work and I don't have the inclination to keep playing with it and messing my line up at this time.
Here is the link if anyone wants to try, I guess newer isn't always better, I think the 166 is a victim of the pandemic and issues with firmware and hardware and maybe Intel owning it now. Moreover it seems to really work for G.fast but not so well for VDSL, and my ECI modem is fine and I have a few spares for now. A lot of money paid for a device that wrecked my line gets very warm and as does the PSU compared with the ECI modem that gives off hardly any heat in comparison and the PSU is cold to the touch, and also less errors it appears and no packet loss. A shame but I dont want to be a beta tester at this price range, even though we all are with new tech really.
https://www.draytek.co.uk/download/support/files/v166_bt_423RC2.zip