Home-brewed modeler

I have spent about 25 hours working on a low-poly modeler that will save to my specific format. My format supports skeletal animation and compressed animations, hierarchies, etc. So far my modeler will allow me to make points, color them, connect them with polygons to make solid objects, and that''s about it. You can make multiple objects and select them separately as whole objects, but can''t do anything with them yet. My question is, is all this worth the effort? Is it worth it to make my own modeler? Should I just use 3DS like everyone else? Has anyone else here made their own modeler before? Bean Dog