Yea mine's always perfect after a reboot. 28mbit down all evening long. It's when I leave the house for work and spend a few hours away that it won't work.
Also, as a followup I have 2 wifi routers and one of them has 5ghz as well, when it doesnt work it does work on any of them.
I noticed the same.
Works fine, then I leave and come back and it gets stuck and Im waiting 5 minutes to load a page.
WTF?