I'd love 6. Even 5 would be better. I was quite disappointed when I saw the limit of 4 in DA:O. The problem is with turn-based - changing from 4 to 6 will mean that fight are on average 1.5 times longer, and that's not taking into account having more enemies to balance difficulty. That sounds like it's going to make fights a drag, especially "fodder fights" with multiple weak enemies. I'm not sure how feasible it is to overcome this. (Boss fights I can see getting better though, as you'd have more tools in your arsenal to think of some creative, complex strategy.)