Good question - given the concern you most often hear about any push fit system is whether the seals will stand the test of time, rather than the body. The only genuine advantage I can think of is if you're using copper pipe, they should preserve earth continuity as the pipes should be earth bonded somewhere in the system. I probably wouldn't use plastic push fit near any sources of significant heat either as that could degrade the plastic body over time. But If I'm brutally honest, I hardly ever use push fit of any kind - I will always solder if I can. Just a personal preference.
Thanks for the reply.
I kinda get the electrical continuity point, but when it comes down to it, surely, these days, often, the conductive qualities are down to the water in the pipes?
Many houses have MDPE pipes that run up to the mains stopcock. From the consumer side of the stopcock, the earthing is potentially flawed given that there might be other plastic pipes.
I am happy to be corrected though.