The answer depends a lot on what you are doing with the software, and for whom. I don't know if you are an Industrial Designer, or surfacing specialist, or what, but I assume you're not an engineer or you wouldn't be using AW to begin with. For creating class-A surfacing, there are only two other products that are comparable to Alias, which are CATIA and IsemSurf. To be fair, I haven't seen CDRS in a couple of years, so I don't know what they may have improved. As a designer, Alias simply blows these other products away because of its powerful tools, history, and intuitive interface. For Alias users who are not really pushing the high end of surfacing, it is possible to get the same results from a product like ProE, although it will be much more painful to acheive.
When it comes to engineering, however, Alias has its obvious limitations. The 2D tools are terrible, nothing is parametric, and you can't create solids. A well-constructed Alias shell can be used in virtually any other package successfully, but if you spend a lot of time creating engineered details then maybe you'd be happier with another software.
Another consideration is the software the rest of your company is using. There used to be tremendous pressure for the designers where I worked to learn CATIA because it would have "streamlined the process", never mind the fact I would have committed suicide after suffering through using that product for a week! The sad truth is, a lot of companies only need about 80% quality from their designers. If integration with the engineers outweighs absolute quality where you work, then ProE or CDRS might be the ticket. If you're looking for 100%, though, you'd be disappointed.
Just off the top of my head, here are some Alias features I don't think I could live without:
Marking Menus
Blend Curves
clean topology - controlling the degress and number of spans in U and V is a must for good surfacing
CV manipulation
interactive evaluation tools
continuity analysis
curve curvature analysis
Align tool
powerful import/export features
extensive history
One software you might keep your eye on is Think3. They are far from Alias for surface quality, but are rapidly improving. It's got the best integration of surfaces and solids I've seen, plus global deformation. And it's really cheap, though not anywhere near an industry standard yet.