Andrew Gabriel wrote :
Well, since I asked that 10 years ago, if I'd used pushfit,
they would be halfway through the life of the O-rings by now.
I generally design my plumbing installations to last longer
than the lifetime of pushfit couplings.
It's not smart to design a plumbing installation that is
likely to fail in my old age.

Second issue is that the chrome is very hard, and the grab
rings often fail to bite into it, and the coupling comes off
some random time later. So you should strip the chrome for
pushfit fittings too.

Third, I'm using chrome to make the installation look nice.
Why would I spoil that with bulbous pushfit fittings?
On appearance, I wiped solder over the outside of the end-
feed couplings whilst soldering them, and then they blended
in with the chrome pipe.

Is the correct answer lol