I use the 5 GHz to prevent interference on my 2.4 GHz security cameras, can't always do that. Really needs to be the other way around to work out well for both things anyway, too much uses the typical B and G bands instead of A. I just switch the B and G signal off when not needed.
Got a problem with my wireless router and phone connecting, but only at night. Haven't shut down the security cameras entirely yet to check if that's all it is. They're not wired to on/off switches. Seems strange anything would change over time though, too. Just thinking related somehow to how AM radio is at night.