I would also add 'greater opportunity for more party banter' to the above list.
The Pathfinder companions in WotR having actual full blown conversations with each other and with NPCs instead of only taking when they are attempting to influence your choices is a freaking work of art.
^This.
And BG2 also had lots of party banter and 6 character parties. I'm still all for turn-based and all that, but I want 6-character parties.
