[ part 1, part 2]
Another important difference between VMware Server and VMware Workstation is that Server doesn't support sound. That means that you can't use it to play back audio or video+audio from one of your VMware sessions the way you can in Workstation. That's something I didn't pick up on when I installed VMware Server, and I may install both Workstation and Server (but not run them simultaneously) so I can do audio/video things when required.
The difference in sound support between the two products is probably because Server uses a client/server display architecture, and supporting sound could cause network bandwidth issues. Similarly, if you are doing things that involve a lot of screen changes (video, games, etc.) then Workstation is probably going to be the better choice.
You can't have everything in one package, it seems. Pity. Still, you can share the virtual sessions between these products, so there's still a bright side to it. You have options, you get to make your own choice.