I seem to remember some saying version 6 was slower than 5, but my associate across the hall was running AC 6 and having the same waiting issues both wired and wireless. He changed his network wiring to CAT6 and said the wait decreased by about 50%.
We have made no network or server changes since version 5 when we started AC and whichever version before 6.3.3 we were using was slow. I thought one of the IT folks at AC I talked to mentioned some improvements in speed that were coming in newer upgrades. Having made no significant change in our hardware and software I can only assume that the upgrade to 6.3.3 was responsible for returning the client server environment of AC to a much more responsive system.
That's all the data I've can think of.