i much prefer CMS systems as they make adding pages and editing them so easy and quick and you never have to worry about messing up the code etc.
I can move chunks/parts of the page up and down by just clicking an arrow which is easier then adjusting the code etc in dreamweaver.
Its fully SEO compatible with a simple mod rewrite and like someone else said before, its good if you have staff or want people to work on the site directly as you can give admins limited access.
When i post a review or something in the reviews section, it will update other parts of my site etc which i like.
However there are loads more upsides, but it can be very expensive, mine is in almost constant development over the last year and i would say ive spent about $15k on it. Any time i want an adjustment it costs me lots of $$$, but with it being customised for my needs, it makes running the so so so much easier.