A bit of a brain dump.
Shared Hosting
From a hosting company's point of view a large pain in the arse, dificult to secure and maintain
VPS
I think there really is 2 levels of VPS
Level 1) 64-1024MB RAM VPS
Level 2) 1024+ (VDS?)
A VPS isnt really less than a dedicated server unless you make it so, they are much easier to manage and fix if something goes wrong and only have a overhead of less than 1% with openvz.
Personally I prefer large VPS's as they are more cost effective to run. Anyway thats my point of view.
Splitice