"I would recommend these over any "copper, or brass fittings" John Guest Speedfix is the best on the market, I have used over 400 JG fittings of all sorts and NEVER had a leak or even a slight weep of any kind. Although 11 leaks on compression out of 37!!! Don't take the chance use John Guest, I have used it on old and new copper pipe with great success."
"Been using speedfit for over 10 years. and would use nothing else. Stronger than commpression fitting. Quick and easy to use. Always make sure there are no dents in the copper pipe where the speedfit connects. Do not use within 1 metre of a boiler. Will last for ever"
""Used this system for the 1st time and will now use this in future in preference to anything else!!! Bought complete set of Joints: Couplers - Elbows - Tee's - Pipe & Inserts. Carefully read the manufacturers instructions and started work. Could not believe how fast and easy it was to complete the job and so neat. Not a single drip from any of the joints. Well worth the money!!!""
"If you're not a plumber and are nervous about using traditional copper weld or compression, these systems are a great insurance - practically fool-proof and so easy to connect. Advantages over copper? More flexible (for large-radius bends), no build up of residue in the pipes to reduce flowrates and, arguable, more attractive than copper piping.
Make sure you buy the pipe inserts to make connections. These can be used to connect to copper piping, but it's not necessarily as straightforward. Can also connect to Hep2O pipes, but the inserts need a little more 'persuading' as the pipes are slightly smaller."