Plumbing with pex in a traditional, branch type would be great but I hate the manifold systems. With traditional branch type plumbing, in a bathroom at the opposite end of a house from the hot water source, the sink faucet might take a minute to run hot then you have hot water at about the same time in the tub. With the manifold systems I've seen if you just turn on the sink faucet it would still take a minute to run hot but then you have to wait the same time for the tub to run hot. Also, any faucets in between would still need to run until the hit water got to them from the manifold. Seems a waste of extra hot water to fill all those pipes when you can branch off.