I have but the next time I put one up a site it will be self coded by me.
The reason for using WP is it's the best of both worlds in terms of ease of use and flexibility. It's the number one blogging software for a reason.
The reason against using it is there just happens to be a tool that does what you want, ie a cms tool, better. WP can be tweaked to mimic others things, but I would rather start with something that is closer to what I was looking for in the first place.
If you want to learn how to build dynamic pages, I still prefer building a site versus using a tool somebody else built and tweaking as you go. Case in point, a person who learns by tweaking WP will be far less likely to know how to deal with security issues since WP takes care of that and it's not something the end user would want to play with outside of installing plug-ins.