i didn't know about them until i used them and came across them, my views on them are my own from my own experience. the connectors in question are normally the ones that come with the pump kit and look like this
i've never experienced the copper pushfit connectors so cannot comment on them.
the shower waste pumps have a 15mm pipe from the tray to the pump inlet then a 22mm on the outlet side, i've personally found them to br troublesome on both copper and plastic pipe and would never use a hacksaw to cut pipe as i have a 15mm and 22mm pipe slice.
please don't create your own views on our work force without knowing anything about us, our multi-traders are people that are experienced and qualified tradesmen that have taken further training to do a second trade, normally a carpenter that has branched out into plumbing. i know tradesmen like to look down on council workers as if they are not real tradesmen or got their qualifications from the back of a cornflakes packet or suchlike but i assure you round here working for the council is one of the best paid and most sort after jobs, there is a waiting list for jobs as an electrician.