I'm glad I live in Seattle... It rarely gets too cold here, so I'm not worried so much about the windows keeping too much cold out....

I love my old original windows (1912 craftsman), even though some of them are painted shut. If I were really enterprising I could probably un-stick all of them.

We did have to replace 4 windows upstairs, because a previous owner's remodeling efforts left some very ugly vinyl windows that were installed upside down... To get architecturally appropriate ones was expensive....we had them semi custom made though so that we could get real divided lights and wood throughout.