I have played trooper IA and smuggler and Guss is the coolest companion around as far as I am concerned. Failed Jedi, ********, self indulgent, con artist, somewhat coward unless has the upper hand, thief on the side, funny often. I didn't like his fish head very much at first but it did fit him well.
"who does it better than guss?"
"Wouldn't you rather have the wookie around today? He is taller than me and loves this fighting stuff." (paraphrase) I actually chuckled out loud when he wanted to go back to the ship and send the wookie down.
Best lines of all the companions I have used.
Oh and if you are into the romance stuff the smuggler lays it down all over the galaxy, never was a big thing with me but there you go.