@the-darkvoid,
Nope .... only works for me until first sleep, after which country reverts back to XT ... and i loose all upper channels ...
However this behaviour seems to be related to 10.10.3 rather than your patch, i was using a different method to active both wifi and bluetooth prior to moving over to RehabMans suggestion and the behaviour was the same.
Prior to 10.10.3 update 5Ghz worked fine sleep/wake/speed .. etc all ok, this is the first time i've experienced issue with 5Ghz (once patch applied) ....
As the issue has remained despite changing everything it seems to me that for some reason either the card or the wifi stack are being reset to its default state after a sleep/wake. ...
Do you use Darkwake ?, if so what value ?, will continue to investigate ..... seems this issue also occurs on real Mac's :-
https://discussions.apple.com/thread/5047252
Cheers
Jay