If you enjoy flying, planes, and space, you'll think you've died and gone to heaven. We thoroughly enjoyed our visit here, but what made it exceptional was the tour led by docent, Sig Crossland. There are tours led twice a day and I would strongly advise you to take one of these tours. They don't just breeze you through and point out areas - they go into the history behind many of the exhibits (obviously they can't cover them all). We thought we were going on a 1/2 hour "highlights' tour, but the tour was 2.5 hours long and extremely informative. Sig patiently answered many questions and made the tour interesting for everyone. You can tell he loves this museum and is passionate about connecting people to it.
Don't get discouraged if it looks like there's going to be a lot of people on the tour - they broke the large group we were in into two groups and with the microphones they have, you can hear everything very clearly.
You can go into the "control" tower at the museum and I'd suggest you do that early as we understand the wait time can get quite long in the afternoons.
The one thing to be aware of is - the only place to eat here is a McDonalds that can get very crowded. You might want to time your eating to "off" hours (if there are any). One option may be to pack something in a cooler and eat it in your car - not from a cost perspective, but from a wait time perspective. Of course you'd have to weigh this against the wait time to get back into the museum since they have to search all bags - the lines weren't long when we were there.
Parking is $15, but everything else is free - a deal that can't be beat.