I've had a clip fail but it was a crap clip. The AP ones are much better.
I dive a one piece harness because I used to have an adjustable harness but never ever ever adjusted it so thought "what's the point" and now use a one piece harness.
On my MOD 3 I had to remove and replace my kit on the surface. Getting out was easy, but getting back in was hard.
Janos
PS - One piece harnesses aren't DIR harness systems. They were in use when DIR was a gleam in George's eye and are part of the system most people call "Hogarthian" (but not in a gin drinking way
)