I decided that it is decent enough and going on the frog to be a jedi for a while was fun but after much playing I think it is not bad. Kashyyyk looks a hundered times better but Kashyyyk is much more complex. I never did any of the quest's just so as I would not ruin it for me. However what SOE said about stepping on lava is true it will kill you in 3 quick hits regardless of profession and medical skills.
Mustafar is by far no way a just jedi place because many if not all quests are important to each profession as far as I have found out. Though rules say I can not tell you everything but I can tell you my experience. For those of you hoping to get a glance at old Ben Kanobi you will need to work for it, it is far more complex then just walking in a room like the themeparks it has many quests which I hope to do some time.
BTW unless you have a lava flea do not drive across lava. That is all I have to say.