I have a few sites that use CMS’s and I have a few that use wordpress, and several that are plain old html sites.
I’ve also worked with sites that use custom CMS’s in the case of custom backends, so far what i’ve seen has been great.
In the case of freebie CMS’s I haven’t found anything I much care for, or but perhaps that’s just impatience.
I find them in general to be restrictive, many basic CMS’s seem to completely leave out SEO, however you can generally find hacks and mods to solve that problem.
I haven’t given up on the concept though, in fact, i’ve just installed joomla on a real estate investing site of mine.. now i’m tearing it down and about to try phpfusion 
So far though, I still prefer writing my own pages.