I was in a bit of a bind because I bought several dozen new AP-205's but needed 6.4.1, which simultaneously depreciated my few AP-61's left. I upgraded two weeks ago. That was a fun weekend because I had to swap out a several AP's at code upgrade time!
The upgrade went well on both my older test 3600's and my new 7210's, and I took Airwave to 8.0.1 as well with no issues. The AP's booted right up.
The only ticket I've gotten so far is that I use an on-controller captive portal, and this one user was not able to load the captive portal with Firefox 30 on a Windows 8 Lenovo Yoga. A bit of troubleshooting showed it to work fine on my other devices, and using IE seemed to work for that user. More testing needed on my part to troubleshoot that issue, but user claims it started happening around the time I did my upgrade.
Aaron
#7210#AP205