Well it depends. You are shrinking your cell size when you do this, so make sure you have acquitted coverage. One quick and dirty way of doing this is looking at the report "nearby APs". Make sure you see adjacent APs with different channels but okay RSSI values.. If you have a decent bit over overlap, go ahead and set it. You can also set the FD value to -77 for the 2.4 Ghz radio. Because honestly, unless you are line of site or in a noiseless environment, 2.4 at a -82 is going to be hosed..
I would do some testing.. Make sure you don't have any spots where connection is okay but RSSI might be poor and then you inadvertently kick someone off.
An example of this is our sports dome.. It's in the middle of a field, only has 6 APs in it. There is hardly anyone it it, so if someone gets has an RSSI of -80 on 2.4, he might do alright, so I wouldn't want to kick him.. etc.. that's the way ya got to think.. then built it to your needs and specifications. There is no one magic number that works for every location. I found that out the hard way
