Last I week I gave Google Sketchup another try and it seems a program you can learn to use quite quickly. If you compare it with GMax I think it has a learning curve that is much less steep. And I think if you model carefully in Sketchup you can make models with it that are suitable for real time rendering. So I think that for some people who just want to make some simple objects Sketchup might be a nice alternative.
But how to get those objects into FS? The free version of Sketchup only exports KMZ and DAE files. You could probably convert them to 3DS, import into GMax and then export, but I think all those extra steps make things too complicated. So I decided to work on a ModelConverterX feature that has been on my list for a while already, support for COLLADA DAE files.
I am not there yet, but I can now read the basic geometry from COLLADA files into ModelConverterX, below you see a screenshot where I loaded the COLLADA test duck. I still need to work on reading the materials used correctly and I guess some testing to see how robust the code is would be nice as well. But with a bit of luck I will have a beta of the COLLADA reader in the development release soon.