It's a tough call for me. While I appreciate dialogue being influenced by stats as a part of the immersion of an RPG and also feel that it may add to the replayability (chose a higher charisma class for additional dialogue options) I feel there is a bit of a downside. We're looking for a type of game that is heavily story driven, a heavily story driven game relies on dialogue. I'm not sure it's worthwhile to gimp the most important aspect of the game because someone has chosen to play a "dumb fighter." That said, I suppose if you can manage to always have a high charisma npc in the party to communicate then great .. but I generally prefer my player character to be the voice as well .. provides for more immersion.