The various CAD software available on the market

Pro/E is predominantly used to design consumer and commercial products other than automotive. In fact automotive is one industry, along with aviation/aerospace, where Pro/E is not the market leader. Pro/E leads in market share in just about every major product category in the US, outside of automotive. SolidWorks has made major inroads into these market segments, but Pro/E still prevails as the market leader for product development (injection moulding, blow moulding, die cast, sheet metal and other manufacturing techniques). From faucets to industrial instruments (lab and portable) to vacuum cleaners to computers (laptop, desktop, servers) to printers to medical equipment to toys to kitchen appliances, Pro/E was the first 3D system in these markets and to this day still holds the market lead. Again, SolidWorks has made major inroads and continues to gain ground on Pro/E. I have always likened Pro/E to VHS not "Betamax", it isn't the best CAD system around but it became the defacto standard for many, eventually DVDs knocked off VHS, so what's beyond Pro/E? SolidWorks or something even better? This is not exactly the best analogy because software isn't tangible and therefore can morph into better software, but Pro/E could get dethroned, so could SolidWorks.

CATIA was developed for aviation/aerospace, not automotive. It was developed by Dassault Systemes of France, famous for the mirage fighter jet and other aircraft. It was developed as a 3D surfacing CAD software, but has migrated to parametric solid modeling and it has some great functionality and ease of use built in to the latest versions. Too bad virtually no US companies outside of Chrysler, Boeing, Honda of NA and their respective supply bases use it. It is still the best at generating class A surfaces, not even UG can out perform CATIA's surfacing capabilities.

UG was originally developed for manufacturing, primarily for writing NC code (APT). Then it was purchased and further developed by McDonnald Douglas (think DC3 through DC10 and F/A-18 Hornet used by the USN and USMC) it went from an automated drafting board with NC code writing capabilities in the 1970s to full blown 3D surfacing and parametric solid modeling (though they still use some other marketing driven term to describe their flavor of solid modeling).

UG-NX is also quite capable and has great functionality. It is the combination of SDRC's I-deas product and UG. I don't find it hard to use and in fact it has some great usability features. Ford Motor Co was SDRC's largest customer. GM was UG's largest US customer. After UG acquired SDRC and merged the two products this left Ford and GM on the same CAD system, UG-NX. That is why Ford will/is migrating to CATIA, budgets permitting - they'd rather share a supplier base with Chrysler & Honda than the General.

UG (now Seimens) writes/owns the parasolid kernel that SolidWorks is built on. Many other smaller CAD companies use this same kernel. It works well as long as you don't translate out of that software to something else via STEP or IGES, mainly because parasolids will adjust the tolerances as needed to accommodate the users commands and in the process the underlying math can become very sloppy or "rounded off". STEP is generally better than IGES, but still the results are not guaranteed.

Cimatron & DelCAM. While both are great as integrated mold design and manufacturing systems, outside of a few niche applications they do not compete with the SolidWorks and Pro/Es of the world.

Visi, VX, CoCreate, SolidEdge, etc.: There are numerous other CAD systems on the market. I find CoCreate worth watching, but don't expect it to gain any market share anytime soon.

Finally I'll address Alias-Wavefront. It is a CAID (as in Computer Aided Industrial Design) software. We use it to develop conceptual designs and renderings. It is great at what it does, but it is the apple in this discussion of oranges. I would not manufacture anything that came out of Alias-Wavefront, not until it has been imported and made manufacture-able in Pro/E or SolidWorks. It simply is not geared for developing manufactured products. Anyone that is using it in this fashion is putting a lot of extra effort into the process.

Disclaimer: This is my opinion or what I know to be fact from being in the CAD/CAM industry for the past 20 years. I don't work for any of the above mentioned companies.