I have already written a review on Dreamweaver MX at https://mouthshut.com/readreview/28023-1.html
Most of what is written in the above review is applicable here, with a few additions which I shall illustrate here. I shall assume that you have worked on DW MX.
What’s New
New Look
When you start up you are given the option to choose your interface as either Designer or Coder. This preference can be changed later.
Once it opens (quite fast indeed which surprised me), you find the familiar DW MX look, but with better colour ;-)
You also have a big screen which gives you various options like Open, Create New and Create from samples (many additions here). If you don’t like this screen, you can disable from showing in the future.
Better Support
The new version includes better support to Cascading Style Sheets and XHTML as well as programming languages like PHP.
Help File
The help file has been improved upon tremendously, with even more detailed instructions.
Checking
DWMX2004 also has good options to check your site for accessibility, broken links, orphand files like its predecessors, but one really useful improvement I found was inbuild support to validate your site as per DOCTYPE as HTML, XHTML etc. Very useful for designers (like me) who want to design sites conforming to the latest standards.
The usual
Most of the features remain same as DW MX and I suggest you read my detailed review at https://mouthshut.com/readreview/28023-1.html on the same.
Also available is the vast collection of extensions found on the Macromedia Exchange website.
Now for the cons
As usual, one of the main negative factors of Dreamweaver is the complex interface. This may scare beginners at first. However once you get used to it, there’s no looking back.
Another thing is that like DWMX, in order to use DWMX2004, you will need a minimum resolution of 1024*768 or above. You can design at 800, but it is too cumbersome.
Price. At $399, the cost of DWMX 2004 is bit on the steeper side and you have to really think twice on purchasing this product.
Links to visit
Homepage: https://macromedia.com/software/dreamweaver
Overview: https://macromedia.com/software/dreamweaver/productinfo/overview/
Features: https://macromedia.com/software/dreamweaver/productinfo/features/
10 Reasons to upgrade
https://macromedia.com/software/dreamweaver/productinfo/upgrade/#01
30 Day Trial
https://macromedia.com/go/trydreamweaver
You will need to register for Free for the same.
As a finishing line, I must state that, if you are a keen professional web-designer, and have the cash for the same, you should consider purchasing DWMX 2004. Ofcourse you can always use the trial version for a 30 day period, but this one software worth having as your own :-)