As far as tool is concerned, I highly recommend you Enterprise Architect. It is very nice and the price is reasonable for a modeling tool: http://www.sparxsystems.com.au/

The use of UML depends on what you are trying to do: Are you working on a new project or on one where you've been working for years? How many developers are in your team? Who will use/read your models?

I usually use UML to accomplish 2 goals. One is to reverse engineer an existing system, and create class diagrams with the important (to me) classes on it and their relationships. The second goal is to show others how a system is/will be organized.

I don't use UML for code generation nor do I think people should be using it for that :)

CRC are a nice technique, although they have nothing to do with UML (not that that is a bad thing)

I have a whitepaper on the use of UML that you might be interested in:

http://www.hectorcorrea.com/DotWiki.htm?topic=ApplyingUmlInYourRealWorldApplications



>I'm trying to get some opinions on UML within .NET.
>
>Who is using what, and your opinions on why it's great and why not.
>
>I initially want to get:
>1) Class design
>2) Reverse Engineer of existing project(s)
>3) Code Generation from classes I create
>4) Use Cases
>5) CRC Diagrams
>
>TIA