Superspeed,
A good third party one here http://www.billion.com/product/vdsl2/BiPAC8200N-wire...
Yeh, for quite some time I've wondered whether the Billion 8200N was a viable router-modem for VDSL2. Broadbandbuyer.co.uk (BBB) insist on calling it a
router, though, not a combined router-modem. This left me confused about it. BBB say that, in VDSL2 operation, the 8200N is a router and must be connected to the BT Infinity modem. That seems to contradict both a comment from a customer review of it at BBB, as well as the experiences of one or two users writing about it on the Billion UK forums.
The 8200N appears to be a one-box solution to VDSL2 connectivity, but I see that Billion has also recently brought out a modem-only VDSL2 product - the 8200M. This suggests that if you already own, say, a 7800N, you could connect it via EWAN to an 8200M and happily run VDSL2. This would be useful for some sort of future "two-wire" Openreach option.
Under a two-wire option you could also use just an 8200N, as you've stated. Indeed, it seems that some users of VDSL2 who are dissatisfied with various aspects of the Openreach modem are not prepared to hang around and are already using the 8200N in its place, as a one-box setup.
As yet, none of these users have said whether, with the 8200N or the 8200M, they're able to get a full set of line stats from the modem. I've presumed also that tweaking of the VDSL line will be prevented in these and any other VDSL2 products that eventually come on to the market - which I suppose is sensible.