In many ways, it’s going from one extreme to the other. My own system is based on static rendering without a database, to the point that the original data itself is kept in RSS-compliant XML files on the site, and HTML files are generated from those. So there’s no programmatic server overhead for retrieval, but there is for authoring, since all the dependent pages have to be re-rendered on the spot. I’m still a fan of this type of system, but I wanted to try something different. WordPress is about as different as you can get: by default, it runs a battery of regular expressions--dozens upon dozens of them--over each post to format it at retrieval time. (Some kind of static caching may be on its way, though, judging from hints in the database schema.) The administration interface is mostly very good, making it much easier to perform administration tasks such as adding new categories than my homegrown config-file-based system did.
Pros of WordPress: very hackable (the good way, by the site owner); terrific setup routines; good navigation controls, easy to set up; well-rounded feature set.
Cons: frequently passes HTML through finicky regular expressions; too much use of addslashes() for my taste, including some double applications; a few bugs in 1.0 (though, to be fair, 1.0.1 final is imminent).
Some changes I made to my own copy include: