While I used it once I need to say that adobe muse is good IF you are creative.
In my experience muse was made for creative artist.
is the coding clean ?
Not really.
I think if somebody took the time you can make a nice and awesome looking website enhanced with a powerfull cms.
My opinion :
It is a nice “editor” for letting creative designer create a website that is complete with their taste.
It shows that adobe is not only for designers and developers.