I have a house with concrete walls and floor that's trouble for Wifi.  I have been getting ok performance from a D-Link DIR-645, but it's now playing up.  Currently using a laptop and variety of mobile devices on Wifi.

So I'm after a reliable modem with the best chance of getting through concrete that's as least as the D-Link.  The ASUS RT-AC68U and Netgear R7000 seem well reviewed, but not sure how each would work through concrete.  I'll probably use DD-WRT or some sort of Tomato firmware.

Any advice on these two routers or any others I should consider?