Copper or plastic pipe with speedfit fittings?

[Gossamer]

Hi I'm rerouting CH pipework to a new rad.
I can solder but its a very tight space in a floor so going to use JG speedfit fittings.
Is it better to use copper pipe or JG plastic pipe?
Cheers.

 

[SandyLyon]

Either, use pipslice if copper, plastic cutter and inserts if plastic.

Make sure pipe is fully inserted, lock off fittings or fit a collet clip