I've always gone the custom CMS route. You get the exact functionality the client is looking for. Their pretty easy to write.. And you UNDERSTAND how it's working... So, when the client comes back in 2 months and says, "I want to alter the way this looks.. I want to add a repeating ad at every sixth paragraph..." You can do it.. With the 'product' CMS's you can't (or it's really difficult) to be that flexible.

Brett