this couch is firm but still very comfortable, meaning it doesn't sink in as you sit but it still has enough cushion. It is quality material. The extended portion of the couch is nice and big, 2 people could share this spot. 
Only issue I had was when I received the couch, one of the pieces of metal underneath the couch was bent (the hole was not a perfect circle) so I had to saw it down just to fit the foot piece inside..but I would think that this is an isolated issue and should not deter anyone from making the purchase because it is definitely a great couch.