I don't know. I can only answer this after I've seen New Moon. Than I can compare the two movies and make my own conclusion. But I think it's too soon to make judgements. Let see first how the second movie works out, they could always ask one of the directors of the first two movies to make Breaking Dawn...
In some ways I think yes, because it's a whole new experience each time. But I guess we'll never know if it was for the best or not, because it's not like we can go back in time and change anything.