I think it's also important to see what tutorials are available for the program, both from the manufacturer and external. Reading the manual is great but sometimes it's hard to understand what a certain tool or plugin can actually do for you. Also look at the price of plugins for the program. My opinion is pound for pound your best bet is Truespace. The program is inexpensive and the plugins are cheap. Also you can get PhilCs' excellent modelling tutorial CD that will give you a jumpstart on understanding the concepts. I hope I've been helpful.