My experience, for what it (little) is worth, is that the question "what modem is best?" depends on your line.
(EDITED: to clarify. I said "router", but meant "modem". My point, below, is that if you have a noisy line,
modem A might be better than modem B, but it could be vice versa on a clean line.)
Although I am crow-flies quite close (200m?) to my PCP/DSLAM, my line goes "round the houses", and connects to my premises
from the last of 2 poles. I'd guess this is far from ideal, and my line hoovers up copious noise of various kinds en route to my modem.
Currently, after a fortnight spell using a VMG1312-B10D, I have INP of 52, INT of 8, and various other ugly
numbers, despite capping my line to 72 Mbit down and 16 down. Not only are the figures ugly, but also the graphs of
eg SNRM/DS. A couple of days ago I switched back to a Huawei HG612. The figures are still ugly, but the various graphs
on MyDslWebStats are now, to my untutored eye, relatively pretty. It seems consistent with my observations that the HG612 handles
a dodgy line better than a VMG1312-B10D. It could well be the other way round for a sane line. (Mine insane line was sold to BT for
about 6 old pence in the 80's.)
I am going to try substituting a VMG1312-B10A in a few weeks. I have a feeling, or hope, in my waters (based on
various posts in these forums) that this will improve things; but no certainty. Anyone interested in my experiments is welcome
to look at SandReck's data on MyDslWebStats. I believe so far that in my particular case, the HG612 hands-down beats the VMG1312-B10D.
In MyDslWebstats, the historical data shows what looks to me like a remarkable improvement late on Oct 5.)
I'm far from an expert on such things.