Anyone been to the Kenny Chesney Country Music Festival (Stadium shows)??

My wife and I are toying with trying to get tickets this year for us and our daughter (13) for the New England Country Music Festival at Gillette Stadium with Kenny Chesney in August.

I have a couple of related questions for anyone that has been to one of the stadium shows.....

1) The show is expected to be about 6+ hours.....Do they allow in/out privileges? If not, could seem like a looooooong time to be there. Then again, we could tailgate for the first two acts and then go in for Zac Brown and Kenny.....Of course, when I go to the Pats, we tend to park north of the stadium anyway, to avoid being right in the big stadium lots........

2) Is it even worth the $25 for Kenny's fanclub for presale ticket access given the size of the stadium? I.e., unless I want to spend $$$ for sandbar or good side seats, it could be superfluous. I would think as long as we have non-field seats, we would be in good shape.....

Other thoughts/strategies for a big outdoor show like this????

We have been talking about this for a few years and I would love to know what you all have to think.........

Thanks ahead of time!!!