The other problem is when you are using a tele lens with a lens collar (assuming you use such a lens) you would still have to unscrew the connector and move it to the lens plate. Using the clamp on the sling eliminates both of these situations. Plus I still feel a dedicated camera plate is superior to a "universal" gasketed (is that a word ?) one.
+1 on both points.
A dedicated camera-specific plate has an anti-twist feature that's better than a rubber/cork surface on a flat plate. Plus, I prefer to use an L-bracket sometimes.
More importantly (to me), I have 7 lenses with tripod collars - the ability to easily switch the strap connection around body and lenses with a QR clamp is very convenient.