No luck for me on the 5ghz ssid . it is fast but drops the connection constantly. Have to reboot at least twice per day to fix "limited connection" issue when connected on the 5 GHz.
I had a similar issue with a Linksys router I had a couple years ago (before the surface pro). I found that setting the router to a specific channel (instead of automatic) fixed the issue. It appeared that my router signal was fighting my neighbors' routers. I downloaded an app for my android phone that was a wifi analyzer and it showed what wifi channels were being used in my area. I then went into my router settings and set the wifi channel to one that wasn't being used. I no longer lost signal from the router.