@ kamikuza
I can only talk for the QRs i had myself. I had zero troubles with 2010 and 2011/2012 also no troubles what so ever. Ah friend of mine had issues with his 2010 and those got replaced by 2011 improved QR and no problems anymore.
I tested it with sand and stuff made it a little heavier but still no problem with one hand.
It does sound a little that your mini 5th had to much tention this can lead to heavy releaseforce. But i'm no expert there. I look forward to the epic CL, i have a testversion at home and it definitly looks and works better. Dimitri is still working on the latest version of that CL because he wasnt 100% happy yet. But so far its a very nice CL.
But i think this is more about the kites.
Both kites are good. If you can test them.