I am wondering whether there are any reasons to NOT use Sharkbite
push-fit plumbing fittings other than their relatively high cost?

Rather than sweat soldering, they seem like a really attractive and
very fast way to install copper plumbing without use of a torch or
solder. I am especially curious to know if they are holding up well,
and are as good as they appear on paper.

Any opinions would be most appreciated.

Smarty