I've loaded the new beta, and am a bit disappointed. The "N" response of the AP is sluggish compared to standard B/G mode. However, for some reason the B/G mode seems to have perked up very nicely compared with the last beta. I am, still using a Apple iMac, so I'm not sure if that might be the reason for the sluggish "N" performance. It didn't connect at 5 GHz before, I'll try doing that today.
Well, it appears the problem with Apple connecting to 5 GHz-N mode still exists. I can connect to 5 GHz using B/G, but I was able to do that in the previous version as well.