I'm building a spaceship. Seems for complex models a scene graph is almost a neccesity. Other than that MOI holds its ground pretty good. Operations are mostly stable, except the notorius fillet function, which is hard to program, i know. Lot of complex situations it needs to cope with. Its easy to reconstruct stuff from edges when things go weird and a lot of other timesavers are in this little proggie.

Good work, Michael!

BTW... I was on Rhino3D beta test also for a year or two...