Thanks Simon and Chris.
Chris. I have always used the good old mitre box and sharp Zona saws for cutting tube and beams I would not use a chopper this is my own personal view and I would welcome anyone else's opinion.
Apart from the NWSL Chopper and the Proses above there are many Styrene "Choppers" or cutters around here are three more.
I would still use a saw for beams and tube. I chose the Proses because they don't use special blades just the ordinary break off blade that can be bought anywhere. Again it's a personal thing. I would like to buy them all and try them but I don't have the money for that kind of thing I'd rather buy something for the layout. Of course if you have the time you could always make your own Chopper or guillotine. Roo.