Running longer is great. If you can run 30-45 minutes then more power to ya. I just think that having to have a pitguy to swap batteries kind of defeats the purpose of electric this point.
Now at the local club level do whatever you like. The biggest problem we see at the lighter turnouts is not having enough folks to pit and also marshall. Its kind of like musical chairs sometimes finding a pit guy. We often end up with folks pitting two cars or refueling while your cornering.
Some of the electric racers who have been converting to nitro dont like that aspect on the club level and have a big interest in converting over to electric for these reasons.