I had some fruity dropout issues with 2.4ghz when I first got the Superhub a few months ago. It was absolutely fine on 5ghz, apart from all the wireless device that couldn't see it!
Now with R30, I switched it back to 2.4 and it's been rock solid. No complaints whatsoever with a Macbook Pro, Macbook, Powerbook G4, HTC Mozart, Nokia N8 and a HP Touchpad all using it daily.
Strikes me the SH was in a very similar state of 'finishedness' to the TiVO when it was first released...