After a few days of investigation, one new Vigor130, a new master socket, and unlocking my old Openreach HG612 modem I've come to the conclusion that there's either some incompatibility of the Lantiq chipset with my cabinet or there's a firmware bug in the Vigor?? I've put a ticket in with Draytek just to see if they can resolve, but I think I'll just stick with the Openreach modem....
Now just need to wait for DLM to realise everything is ok now!
Re: Draytek Vigor 130 SNR fixed... with Huawei HG612
I've previous had issues with the Draytek 2862 with a Lantiq chipset on a Huawei cabinet - although I believe the 130 has a slightly older / different chipset.
I'd give the Draytek a second chance on an ECI cabinet tho...
BDCM 63168 sits well with my Cabinet (not sure of the line card version in the DSLAM).
If you want to move away from a hacked BT modem Cisco 887 routers with a xDSL port has the 63168, they are aging and end-of-life so can be picked up for 20 quid or so. There are fanless versions, so worth poking around eBay if that's what you need.
Look for IOS 15.4 or above and modem firmware 39m_B_38h3_24 or newer. I'm not sure how close the processor would be to bottlenecking at 80/20 flat out but if you just plan to use it as a transparent bridge and open the PPP connection from a router behind the hardware is undertaxed.