Are they standard jubilee clips or slightly bigger / more heavy duty?
Ah fair point. They are jubilees albeit with much deeper, bitier teeth and a larger screw.
Another thing to bear in mind with the jubilee clips is that they should be stainless steel. Over time water/salt etc is going to get into your engine bay and you do not want the clamps to be rusting up.
Can't imagine my £2 jobbies were rust-proof.
Having said that my old Forge CAI used standard cheapo jubilee clips and that was on the car for 2 years and showed no signs of rust or loosening in the whole time I had it.
I'm not dismissing the issue at all but my experience (so far - not had it on as long as you Warren) is that the jubilee clips are fine.