@The.racking.monkey wrote:
You'd be better posting snapshots of your config so we can see what's enabled (not default stuff). That way, we'll know for sure.
The only thing that you would "lose" potentially is old fashioned AP load balancing. From a purist RF engineering perspective, it's not as good as the newer functions that replace it (which are technically better), but the fact is I have seen good results with it in very specific circumstances (schools with single radio APs and old laptops). If you are relying on it, you might need to know this. I have in fact seen some customers deliberately stay on old codes for this reason even though it's not supported officially anymore.
Old fasioned AP load balancing did not take the band of an ap into account so the more modern version is more inteligent.
The 6.x code train does not support the 200, 800, 2400, SC-I, or SC-II controllers is probably the biggest change I can think of.