I haven’t used them, but have a friend who works for our local water utility and he says they use them all the time. I just replaced my HWH in Oct. Could have saved some time using them, but I’m still on the fence…. or maybe just old school.
We use them occasionally but more tor a temporary fix when remodeling bathrooms and we have to cut off pipes to remove cabinets and the like.
They are quick and easy. We hane the plumber cut them out when they get to the job to do their rework. Typically we do not leave them as permanent connection
I had a drain valve go bad on my camper this weekend, Headed to the nearest little town to find a replacement, The only thing they had was a Sharkbite, Hadn’t used one before but I really liked it, Cut the line and slipped it on. No drips yet.