That nighthawk router looks slick, love the way they added the antennas to the sides. 6 antenas in the back just looks like overkill but the side mount is very subtle. I've always bought ASUS routers but I just might make the leap to Netgear on this round.
600 Mbps is actually possible now on 2.4GHz: see this article to provide explanation of channel width to speed rates --> http://gigaom.com/2014/06/12/next-phase-of-wifi-80211ax
Using 40MHz channels "theoretically" allows up to 800 Mbps on 2.4GHz, and up to 3.46Gbps on 5GHz using 160MHz width channels. You have to support 4x4 MIMO antennas to make this work client/server so keep that in mind. Most phones have 2x2 and most wifi adapters are 3x3 currently