I'm looking to replace a Gemeinhardt 3OSB, and have found both the Gemeinhardt KGM Standard and the Jupiter diMedici, used, for about the same price. Any thoughts on which would be the better instrument?

I used to use a Gemeinhardt 30SHB for my backup flute. Then I came across a Jupiter diMedici. Its wonderful. I didn't miss the Gemeinhardt at all. Different maker, different scale, smooth mechanism ... diMedici is a nice choice in my opinion. But you have to play both, if you can, and decide for yourself.

The KGM is basically just the 30SB you have right now so it wouldn't be an upgrade. Between the two I would definitely go for the Jupiter. If you want an upgrade and are trying to keep it at a lower cost, you could always look for a nice used Yamaha 221. That would certainly be upgrade to the 30SB that you have now. You wouldn't be paying the extra cost for holes or a B foot that is rarely used either.