Well mine was a useless endeavour, my Samsung (Fame) doesn't even see the 5GHz network, it doesn't seem to be supported!
Same for 4th generation iPod touch, 5Gz apparently not implemented.
iPad 2 and latest iPad mini, both work on 2.4GHz as well as 5GHz, and
generally seem to have a predilection for 2.4, given the choice. It is vague though, at least once the iPad 2 chose 5GHz when 2.4 was available too, not sure what was different. I wonder if recent history of connections may play a part in choice of networks?
The Mac Mini actually seems to prefer 5GHz when it has a free choice, but doesn't seem to cope too well when I disable the connected signal, one on occasion it went into a strop that lasted several minutes, timing out on every attempt to register. Then it suddenly worked again, after fiddling with various things that shouldn't have had any effect.