I have an Asus DSL-AC56U and it works well, apart from one annoying fault. The 2.4GHz wifi band is stable, but if I connect via 5GHz it works for an hour or two and then stops transmitting. The wifi signal still shows full on my computer, however nothing happens when I try to reach a page.
Until now, the only way to get around this has been to enter the router's control panel, locate the 5Ghz tab under system status, then click apply. At that point all works well again for a couple hours until the whole process is repeated.
For an easy life I've just been sticking with 2.4GHz, but I'm curious why this would be happening and if there is a solution?