I'd never start out with a free/shareware 3D app if I could get my hands on a professional tool. While working with 3D Max or Maya might be a daunting task to begin with, at least you work with industrystandard tools which can basically do anything you'll ever want. You can be sure it'll be updated and supported in the future, there's huge amounts of stuff available for it and most importantly you use the tools professionals use. Which is very good to put on your resume if you ever want to get a job in the industry. While Milkshape and the like are pretty good at what they do, they are IMO the equivalent of MSPaint versus Photoshop.