My old Metcal MX500 soldering iron is made in USA, my new one is made in China. They are made to look the same when viewed from the front, but the casing has been redesigned on the new one and I suspect that the internal circuitry would probably have been cost-reduced as well - there were quite a lot of nice parts used inside the old one. So far the only problem with the new one is there seems to be a magnet in the stand that somehow shuts off the heating when the iron is in the stand. It reheats quite fast, but not quite fast enough for me. I might remove that magnet. I think it might have been done because they offer a warranty on the tips, and we have had quite a few fail and be replaced under warranty. Perhaps they are trying to extend the tip life to cut their warranty costs - just my guess.
Chris