[Farhoof]

I use clip fx all the time and haven't noticed any issues regarding copy/pasting, though I exclusively use the menu from the alt+6 window (which programmed on my mouse for quick access).
Performance is also no issue here.

The only issue I have is when I change a parameter the first time it doesn't play back right away. I have to 'touch' or change the parameter again in order to hear it.

It might get messy selecting multiple clips where each had a different clip fx starting point. The alt+6 window will only show one of them but applies the parameter you change to all of the selected clips (leaving the untouched parameters intact).

What parameters are incompatible by the way? It seems to me they all match the channel strip? All besides the 'fx chain order' and I think the output trim, or am I missing something?