The QR plates will be the weak link in any Manfrotto product
You are so right!! I love Manfrotto heads, tripods, etc., but their QR plates are the absolute worst!
Why? I have used Manfrotto tripods for years and never had a problem with thier QD plates..
I just happen to have a spotter sitting on a 128RCNat next to me... the release catch on the head also has a small locking "pin" or catch and when thats used, the main release catch simply can't move? To be honest I hardly ever use that feature and I've still never had a problem..
I have another Manfroto with a 484RC2 ball head, It has essentially the same release catch and locking "pin"; again I have had zero problems with it.