Reason why I suggest demos is because most of the high end modelers have splines, extrudes, nurbs, ubernurbs, bezier, skins, etc, etc, but some are more intuitive on the interface than others. LW for example has text buttons so you know what tool you are selecting. EI Universe has text categories and icons that represent the individual tool in the category. Easy enough to learn. Rhino and Maya are icon only and you have a lot of symbols to memorize. TS and Amapi have unique interfaces that some love and others hate. So take it for a test drive first before buying, and test drive them all to compare features.