Well, there are two different mindsets to those questions.
The good and bad to going to an early regional is that EVERYONE is new to the game. Teams are still trying out different strategies, and robots don't have any modifications based on prior competitions. Early regionals generally tend to have to have lower scores, since everyone is inexperienced (not taking into account some teams practicing beforehand on their own).
In a late regional, teams have learned from their previous successes and failures, and may have changed things due to those. A newcomer would most likely be lost among the sea of 'veteran' teams. And, for the teams who haven't yet competed in competitions, they have had a chance to watch webcasts of other events and plan strategies accordingly, and also decide upon possible modifications to their robot.
All considered, if I was attending a regional simply to win, I would probably attend an early, week 1 regional, since these are usually the easiest. Although I have never ran nor volunteered at a regional, I would probably sign up for a later regional in that case, since those are generally more exciting and fun =). Hope this helps!
