b. Compared to Copper piping for home usage, is it generally more
expensive or cheaper ? If more, why is it used (at all) ?

Sharkbite connectors are horribly overpriced/expensive. I considered PEX
until I found out how much the connectors cost. If you can find an
inexpensive way to join PEX tubing, it will be much more cost effective.
You can get connector kits and make your own, but I don't know how much
those cost per connector.


d. Would you use it in your home, or still prefer Copper ? Why ?

Copper. One main reason - I don't trust the PEX connection process. The
push on connectors use rubber o-rings to make a seal. Know what rubber o-
rings do after 20 years? Yeah - they leak. The clamp fittings clamp the pex
to pipe, but again you are clamping flexible pex to pipe, and it's going to
leak sooner or later. My copper job will be in this house working
flawlessly when I've died of old age. An equivalent PEX installation will
be leaking like a sieve by then.

I may be wrong, but I've seen a lot of clamped pipes and o-rings in my
time, and they all leak sooner or later. Until they come up with a
inexpensive PEX connector that will last 50 years, I won't use it anyplace
that I can't get to it quickly and easily for maintenance. Keep that in
mind before you seal PEX into a wall - when it leaks, you will have to tear
the wall out, and if that happens you will wish you had used copper (at
least I wished they had used copper - I would not have had the broken
platic pipe to start with). My neighbor is likewise cursing cpvc - he had a
similar experience a while ago with breaking cpvc in a wall.

I also admit to some bias against plastics in general. I just spent a week
ripping out cpvc and replacing it with copper. We had a pipe break inside
of a wall and it made quite a mess. I'm not sure why it broke nor how
durable the cpvc is supposed to be, but I do know I'm not the only one
around here with broken cpvc, and I also know my copper job will be there
for many years without leaks.