Mikrotik looks cool, never heard of them. But they only have one 5GHz (802.11ac) router, and it seems it came out recently? Not sure how I feel about jumping on something that new. I know nothing about the chipsets they use.
For wifi they use only Atheros chipsets because they write their own drivers and changing chipsets would require a complete rewrite for some of their custom stuff.
They had devices with 5 GHz before, just not in their SOHO devices. I've got two of their SXT lites (5 GHz) with directional antennas and my wireless uptime between them is around 70d.
Btw, the interface of their routers is a bit … verbose. I like it, but you should definitely have a look at it before you buy one of their routers: http://demo.mt.lv/webfig/
Even their cheapest devices come with a full copy of their OS, so you could just buy a hAP lite (~$25) and see if you like it. I did the same and never looked back.
