After some recent experiences, my advice now whenever someone asks what router to use for FibreMax (or gig) is "A Huawei 659b, or the one your RSP has supplied"
The 659b recommendation is because I have done extensive testing myself on it and know what it can do - as have others I trust.
The fallback of "the one your RSP supplied" is based on them being reasonably competent and supplying something that works.
In _ANY_ other case, regardless of cost or spec, my answer is "Try it yourself and if it doesn't perform to expectations, try a Huawei659b"
I _KNOW_ there are some routers out there that do a fine job on Gig fibre, but in the last 2 weeks I have come across 3 that should, but don't.
Cheers - N