I've heard of the same issues @itspizza as they're all over the Amazon reviews. Seems that later firmware updates generally fix most of these issues or at least they did in the older models (such as the N66U), but maybe they just haven't gotten to that point with the AC66U yet? A lot of people talking about using Merlin firmware as well as it's just a customized version of the official firmware with a few improvements and bug fixes.
@Reisz I'd be interested to hear how it fares for you into the next few weeks and months. Hopefully updated firmware should help alleviate any issues of degrading signal that some people are complaining of in both the AC66U and AC68U. Otherwise that router seems to be pretty feature rich. If things go well for it I may upgrade to it and sell the N66W second hand.