Copper an PEX are pretty much the standard here with CPVC being the choice of the "Handyman" Oh Boy! I realize that a pro can do a nice job with CPVC a I have seen some nice work pics by others...
Mexifornia has some open ended code applying to PEX. In some areas its okay and in others its not. As I understand in the next code revision it is probably going to be approved statewide. I recently read somewhere that they are currently doing the environmental impact study on it in preparation for its approval... I wonder what the California warning label will say....
PEX lends itself very well to a repipe situation and propably could be compared to rewiring a house with BX vs. Conduit. As with any material the innstallation craftmanship can vary widely. Ranging from bundles of spaggetti everywhere to a simple neat installation. I am not a fan of the home run installation as every fixture gets spaggetti from the source and each fixture has a hot line that you have to wait for the hot water to arrive at. I would instead size the tubing correctly and run it similar to the copper or, in a large home but individual bathromm groups on small manifolds making hot water recirculation loops possible which is not possible on homeruns.
As far as what to use there are quite a few out there. I would say that Wirsbro/Uphonor is the best, but, the tool is expensive and probably not worth it for anyone other than a plumber doing new construction. I am a repair plumber and am faced with working with whatever the customer has installed. The Wirsbro system is not compatable with all the other systems. My choice rather than carry multiple systems was to go with one that was relatively inexpensive yet could work with any system. This is the system I selected.
http://www.watts.com/pro/divisions/potablepexplumbing/learnabout/learnabout_cinchclamp.asp
The one tool does any size and any type of PEX so it works well in my application.
Check with your local authorities to see if PEX is approved in your local area.
A note on PEX: There are 2 Class Action Lawsuits against 2 separate manufacturers. Both suits involve failures of fittings.
Kitec's suit involved dissimilar metals in that there is an aluminum layer in their tubing that came in contact with the fitting and under aggressive water conditions corroded the fittings causing them to fail. As an electrician I'm sure you recall some problems involving aluminum wiring... Aluminum worked it just had to be done right!
Zurn's suit involves a fitting failure in a cheap casting, machined too thin, at too high a speed that breaks. Made in China go figure!
These suits in turn bring out statements that I'm sure were common as the materials used shifted from Knob & Tube to BX, and later to Romex... I'm sure that more than a few "old school guys" fell behind as they waited too long to adapt to the new methods and some of the "new school guys" got burned on things that had developmental problems like the aluminum wire. Our trade has had these same problems in the 80's we went with a plastic tube called Polybutylene only to discover that Chlorine in the water had some disasterous effects on the system... Oh Boy! The rest of the world went with PEX and it does have a good track record and now its new to us. The guys who got burned on Polybutylene are hesitant to go with PEX and cite every problem as gloom and doom. Will they turn out to be the dinosaurs of the trade or, will they be the lucky ones that avoided a wrong turn? Time will tell!