TurboCAD 3D Macintosh

Need to know from users of TurboCAD 3D Macintosh, is this a popular application of it's kind, what issues are there with it, what alternatives should I consider? My requirement is for the design of gearing systems i.e clock mechanisms and clock dial design and clock case design. My computer is a MAC mini G4 with 1.5GHZ, 1 GB Ram and a graphics via ATI Radeon 9200 and Display Type: LCD Resolution: 1680 x 1050 Depth: 32-bit Color
Core Image: Not Supported Main Display: Yes Mirror: Off Online:Yes Quartz Extreme: Supported Rotation: Supported
appreciate any advice.