Web app vs. local client

Starfox

What are the pros/cons of implementing a program as a web app versus a client that one would download? Here is what I have thought of so far, but I'm not sure of any of it. Correct me on anything if I'm wrong:

Web:
Pro - if it runs in a browser, it runs pretty much anywhere
Con - may be limited by the performance of your server, internet connection, may not be able to use your computer's power to the fullest extent?

Local client:
Pro - Possibly able to tap into more of your computer's horsepower
Pro - Don't need to worry about connection speed, stability, etc.
Con - Platform dependent

What haven't I thought of?

Rym

Java Webstart clients can use your computer's horsepower, don't need to worry about the connection any more than a local client, are just as stable, and are platform independent.

George Patches

But require the Java Runtime Environment.

Rym

But require the Java Runtime Environment.

Standard in any reasonable environment. Also fully backward compatible in any reasonable environment.