CAD = Computer Aided Design. It is a class or type of application, like Mudbox, Zbrush, and 3D Coat are all 3D *sculpting* applications, or Terragen is an *environment* modeling/rendering application (although CAD is actually more technically and specifically defined; CAD programs are specifically oriented toward actual practical, functional product, industrial, and architectural design).
What I see is you casting a very broad "net", trying to incorporate or try a lot of different things. This is good to a point, but I get the feeling you're looking for "ultimate" solutions, and perhaps that you think maybe there are good/great solutions you haven't heard of or tried yet. I can all but guarantee you that isn't the case, there certainly is no magic bullet, and most of the time what you are familiar with and can get your hands on (e.g. Maya) is going to serve you better than trying to find some other better program and then learn it to equivalent skill level. IF you're starting at zero with no experience, then learning the "best" tool for your particular needs is a good goal, but what is best is highly debatable and subjective, and given your broad interests in modeling and rendering I would venture to say that in fact no one tool is going to be "best" for all you do. You either need to accept the sacrifices inherent in the tool(s) you have selected, or get fluent in a lot more different packages (very time consuming and challenging).
But mainly I just want to communicate that I think you're aware of all the actually applicable, useful options at this point, and have probably tried many - if not most - of them. There is not likely to be some much better application out there that you aren't already aware of. If you hear of some new thing and it sounds like just what you need, that's worth looking into, but the best way to do that is *not* always just to download it if it's available, this can be more time consuming than necessary when often just looking at the feature list or forum discussions will tell you if it's generally used for your kinds of purposes. So basically, if you like what you have (Terragen, Maya...), that's a fairly well-informed decision at this point, and a pragmatic one as you pointed out, due to cost. Someone who knows their tools of choice extremely well is generally going to be more productive than someone with a "better" tool who knows less *about* that tool and how to effectively use it. So my advice is to make the call ASAP as to whether you're OK with Maya as a modeler and if your decision is yes, then stick with it, learn it inside and out; if your decision is no, settle on a different option quickly, and learn it inside and out. And most importantly, know that no matter which software you decide on, it won't be good at everything and you'll be frustrated sometimes by its limitations.
- Oshyan
