i used it on my last playthrough because I was a little tired of trying to accommodate the party members I needed with the party members I wanted. To be honest, the game is easy enough with the regular sized party, and since there isn't any disadvantage to having more people with you (XP isn't divided like Baldur's Gate and Icewind Dale, right?), it makes things very simple. I'd recommend using the cheat to see more of the party interactions and interjections, though. Maybe after you've completed the game a few times, or up the difficulty level at the same time if you're a vet.
Well, the party size in MotB was reduce (annoyingly, to the point where you have to leave ONE person out...) from the OC's number, so lotsa people cheat around that (not by increasing party size, but just by adding characters using the command).
I wish for this night-time to last for a life-time