Quote - One thing to keep in mind: units in 3D modeling apps bear no relation to real world units, they only describe the relative sizes of objects to each other.
With ODE, things are different. In order to do physics calculations, it needs real world units. One ODE unit equals 1 meter, 1 kilogram or 1 second, the standard international units.
It might be a good idea to adjust imported object sizes to these standard units, so you won't have to scale everytime you send something to ODE (or receive something back from ODE).
Kerkythea is a physics based render engine, and just like ODE, it expects standard international units like meters, In that regard, combining ODE for physics with Kerkythea for rendering would make an even stronger case for real world standard international units for the modeling/posing part of the application!

Let me second what was written up there... using real-world units may (though not always) mean a loss of flexibility internally, but it helps out everywhere else (as well as helps out the customer/user to boot).

/P