I'd probably use the pex. Keep in mind that the interior diameter of pex is smaller than copper, so your volume would be lower. Depending on the fixture, you may want to run 3/4" (say the tub filler, washing machine) to obtain max flow rate for those high-volume devices. Outside hose bibs, too. Things like faucets and toilets, no problem with the 1/2", as they are flow restricted normally anyways. I like the Uphonor (expanding) tubing and fittings...all pex pipe has memory, so on an expanding system, it is always trying to return to the original shape, and thus is making the fitting tighter. On a compression ring version, first, the fitting must fit inside the pipe, further restricting the flow, and then you need to crimp it properly to make the seal. The tubing is trying to expand back to it's normal shape, loosening the crimp if not done well. The only gotcha is the cost of the expander tool verses a crimper. pick one up used, or rent one, or buy a new one, then sell it would be my choice.