Short and sweet; got set up with BigPipe fibre recently (excellent service btw) and just quickly bought the cheepo Archer C2 since I hadn't put much time into investigating for a new fibre modem.
The ethernet has been fine (aside from the odd connection hitches while online gaming etc) but the wireless has started to get frustrating.
I've always found that $200-$300 is a sweet spot for good modems and the ASUS RT-AC66U and Netcomm NF8AC fall in that region, but I would spend a bit more if someone could highly recommend something else. An important thing for me is stable performance for online gaming.
I had a very positive experience with ASUS N55U on my previous DSL connection which is why I am leaning towards RT-AC66U.
Thanks for your time!