Originally Posted by SteveO

Very true.

Personally though in the real world when you are working as a plumber for a living you never use them. I always cut the tube with a clip-on pipe slice, use wire wool, small amount of flux in the fitting, then solder.

I have noticed that my local college is now teaching the pipe expander method mainly due to trying to keep materails costs down.

Yes they work, but not for me IMO.

Its a personal choice