If I use plastic always hep,good sound joint as far as plastic goes,however in early days did a few showers were I took hot and cold from bath suppliers,run plastic up inside wall to shower unit and fitted push fit speed fit,was not doing a lot of joints,one tee and a couplin, you may say not put in right,inserts used and had two that failed one was after a few weeks and you could see the mark around the pipe that it had been in the fitting correctly
Have been called out to a few floods (not my puddles I may add) because of plastic fitting popped,all speed fit and installed correctly,I would add have been to properties were thier white fitting are now yellow,still sound but do not look that good
When i started out people used to moan about yorkshire fittings because if the ring in the fitting making it look bulky,so if we used ,had to use out of sight and end feed when in view or bend up to rads,if that was the case then how can anyone use visible plastic push fittings today,went to a new extension the other day,boootful job
,lots of glass,granite work top,nice wooden kitchen,those posh large cream smooth tiles on floor and designer rads with pipes coming out walls then with hep push fit elbows on to take pipe up to rads,looked right bigs ear,even when you looked under sink,with all the visible plastic pipes and fittings,all worked ok but looked c**p and thats the only way to describe it,still say I can do the pipe work under sink faster and cheaper in copper than in plastic and looks 10 times better,but apparently soldering requires some mystical skill and a naked flame,oooh
Anyway maybe speed fit have improved over the last few years but as someone said they are good for temp capping pipes on first fix to stop plaster going down pipe work but that is about it
In year to come,there is going to be a lot of work to be had replacing these plastic fittings,especially the hot pipe work,maybe thats why the powers that be are trying to train as many plumbers as possible in preparation for the great plastic fittinggate scandle