[jeff5may]

Vaulted ceilings look nice, but they make heating and cooling the space they cover much more difficult to heat and cool. No matter what you do, the hot air stratifies up there. In the summer, it's not so bad if you keep the air still in the area. In winter, much of your heating energy will live there, keeping no one warm. If the vaulted ceiling vents into the upstairs, and everyone stays there, the effect is not so bad. But then when they go downstairs, you know what happens. BRRR!

For plumbing, PEX is hard to beat, especially with a manifold and solid runs to points of use. Besides not needing to glue or sweat fittings, if the pipe ever needs to be replaced, pulling a solid run from the manifold to the point of use is pretty durn easy compared to hacking and figuring and splicing with whatever.