I have both frequencies on my home network. Which one should be used for which functions on my iPad?

I have a dual-band router as well. I've been keeping my iPAD on the 2.4 frequency and have had no issues. I haven't tried 5GHz

Since my iMac has 802.11n built in, I prefer to keep my Airport on 11n/5.8 Ghz to avoid conflicts with my 5 or 6 neighbors that are on 2.4.

It also makes me feel a little more secure since no one around here is on 5.8.

I've got a Linksys e3000 which is their best.....and have no luck with 5K. Maybe it's my house and the walls but my 5K signal is not strong about 30 feet away. No problems at 2.4K.

Just got my duel band router setup today and tried both the 2.4 and 5 GHz on my iPad2.
Have no problem connecting on either, but I notice the 5GHz has weaker signal strength. That's with the iPad setting about 2 feet away from the router.
Speed wise I see no difference so am leaving it set at 2.4 for the better signal.