I agree with your aesthetic sentiments. I once saw a piccie of a very vintage radio (sorry, "wireless set" :-)) where the wiring was done in dead straight lengths of about 16 gauge with perfect 90 degree pulled bends - like a tube map in copper. Nicely bent and joined copper pipework is like that. However in terms of getting a job done soundly and to a reasonable price for something like central heating in a furnished house you can't beat plastic under the floors and out of sight (with just a bit of copper where it's on show).