I've been using WordPress for most of my sites from years now. Tried CouchCMS just out of curiosity and the results turned out to be great. Loved it totally. Especially the ease of use makes it a beginner friendly CMS.
I wouldn't recommend CouchCMS with WordPress. You can easily find solution for WP issues and there is a huge community behind it. CouchCMS is a newer cms. What I like about Couch is that it is lightweight.