I believe in a more open type of roleplay where the roleplayer has just about as much input as the GM, considering of course the Gm's ultimate dream. I don't have much of a different attitude (this is more offsite than here as I haven't GM'd too much here) when being in charge vs being involved besides being a bit more firm at times on keeping things on track. I try to take the more fair perspective when judging things in general, as a player and as a GM - that perspective might come out more when it's me making the descisions, but it's still the same me. That said, I understand folks that adapt differently as player and GM. I do not, however, think one should act ultra-serious and treat folks like strangers - a GM like that doesn't have me in the roleplay, and that's about all there is to it. Gm wise I treaft folks relatively the same... which means I would be friendly with them.