i learned alias in school, had an internship at alias, and have been an alias user at an automotive company for over 5 years. I have also recently downloaded the free beta of rhino for the mac platform at home.
alias has had its issues with releasing broken tools and half hearted attempts at competitive functions in the past, but with autodesk at the helm now i believe they started to rectify that with 2009 version. they have also started to clear out the vestigal tools from the days of yore. i am a born and bread alias guy, and have a hard time wrapping my head around other CAD/CAID packages if only for their different workflows. i have also been fortunate to use it in environments where there is a robust support stucture like at the auto company i'm at. but for the furniture work i do on my own time, outside of my day job, i've adopted rhino, because it will likely be priced right when it goes full commercial ($65K pretty much prices out all but the most succesful independant designers) and has a good reputation and base functionality to what i am accustomed to.
one thing to realize is that a lot of the development of alias is funded by its biggest customers, so the fact that alias doesn't cater to the little guy is no suprise there. while $4K retail is pretty reasonable for the lowest level of alias, i've frankly been spoiled by always having access to the full blown version in my career and would rather learn a whole new package than work with the basic package feeling hamstrung by its limited functionality.
i've found the beta of rhino to be pretty cool, and intruiging, but like i said, its hard to break out of my alias workflow and learn something new so that's a huge personal challenge. right now in rhino, i'm still bogged down learning the alternative terminology for the same processes ("align" in alias is "match" in rhino, etc). its made me realize though that the biggest asset of alias versus all others is the marking menus and fully customizable GUI. like was mentioned above, i have a hard time seeing how i will be as productive without them in rhino... i do things so fast in alias, enabled by the marking menus, that i'll do several sequencial processes intuitively without even thinking about it.
alias is still a far superior tool in my opinion, especially in a corporate environment like i am in now, where there are internal structures devoted to support, developement and training issues related to alias. however, on the "outside" in my personal work, i could never imagine how i would be able to (legitimately) acquire the software as i would want it due to the cost and deal with the support issues like those mentioned above. as a little guy, rhino makes all the sense in the world, and i look forward to learning more about it.
another tool to check out, if only to make it interesting, is solidthinking
, supposedly developed by a former alias employee that seems to have several fairly high profile users and similar surface modeling functionalities to both rhino and alias. i downloaded a free version of this as well, but you can't save or anything, so that pretty much kills any motivation to actually do an in- depth try out of it