Copper water tube.......

Has to be the oldest plumbing question in the book, but I can't seem to find a direct answer. 1/2" CWT L or M (red or blue) for residential application? Running new supply lines for shower valve, wet bar, laundry sink and washer hose supply box this weekend. Any preferences. guys? Seems to run about 40% more for the thick wall type "L". Do I need it?

personally I would never run type M in my house even though it is allowed by code...
I don't like the thin-walled type M tubing tor pressure piping...

When replacing pin holed (M Copper pipes) we are replacing them with (L). I have not done the reading on whether or not this is a real solution or a "thicker band-aid". These (L) replacements have occured at repair calls.

When I have been on partial or whole house re-pipe jobs the M copper has all been replaced with CPVC.

tube

In this area, and those where I have been previously, "M" is the material of choice for residential installations.

I would install what the local requires. The town I live in requires L, about half the towns I work in require L.