I had to ask a coworker as a lot of this has happened before my time here.
Current version is 5.8.6.5 on the 9610 and AP's. Users are using 9090's,92N's, and TC8000's.
We have tried updating some guns to latest version and fusion driver and it did not help.
Not entirely sure about the version on the 650's, but we believe it was 5.x.x
With the 650's, we did not use rf-policy.
The 650's had external drop down antennas. Our current 7522's have internal antennas.
WLAN profile is the same.
Co-worker stated that we rarely had issues when we had the 650's. Now we always have reports of issues with the rf guns dropping.