I bought a Netgear "AC1450" model a couple years ago, since it was on sale and is 100% identical to the R6300, and uses the same DDWRT firmware (thereby making it an R6300 once flashed to DDWRT). At the time, it was a steal at $60 for a refurb and it has served us well. I'm happy with it for the most part, but we moved to a much larger home last spring and there are certain spots in the house that lack connectivity and there is zero signal on our back porch. I may end up setting up at least one additional wireless access point in the home since I had ethernet run to a wall plate on each floor (with the middle floor getting two in my wife's office to accommodate the modem and router), and it'd be fairly easy to hook up a router at least on the 2nd and 1st floors... but I'd kind of rather avoid having more networks crammed into the same house if at all possible.
The retail store I work at has some left overs from Black Friday and since people aren't too tech savvy in this area, there's still a pile of Netgear's fairly-new R7500v2 Nighthawk X4 routers which support MU-MIMO. They dropped from $145 to $125 to $100 but will likely drop lower. I'm sure they are great routers, but... is MU-MIMO really all its cracked up to be? Is it that big of a deal? And is this router likely to give me better coverage? I know it "looks" like it should, with all those huge antennas vs. my R6300s total lack of external antennas... but I can't seem to find anything online that indicates that these are significantly better in speed and range than the R6300.
Like I said, I'm fairly happy with my current setup, but its hard to pass up a chance at a top tier (consumer grade) router at less than half the normal retail price.