Likewise, I took the tour in March and had no issue with 2 x D700s, one of which had my 70-200mm lens on. But, there are other issues you should be aware of:
The buses used have very heavily tinted windows.
The tour I was on was full, and I was lucky to get a 'window' seat.
If the bus is full, you've got no opportunity to move from side to side to shoot different planes.
What you can shoot will be dictated by which side of the bus you're on and where the sun is at that time of the day.
While the tour is interesting, from a photography perspective it isn't great.
Now the good news - Pima Air & Space is a fantastic museum and there really aren't many issue from a photography perspective. I can offer a couple of tips though:
Get there early (I think they open at 9am). Obviously, the best photography conditions are early morning and late afternoon (it closes at 5pm I think). I would suggest shooting the outdoor stuff at those times and the indoor stuff during the middle of the day.
I visited on two consecutive days, a Sunday and Monday. I was surprised to find that it was a lot busier on the Monday than the Sunday. On the Sunday I had no issues with anyone getting in my shots, the Monday was more of a challenge in that respect.
The planes are generally well laid out and significantly less crowded together than at many museums.
It's a big museum with lots of planes - try and plan ahead what you're most interested in shooting.
This is the only shot I've uploaded so far from the bus tour:
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Photo © Steve Brimley
But lots from Pima:
Time flies like an arrow. Fruit flies like a banana!