FlyingGoggles
I did the "40 minute" tour last Sunday (although it lasted much longer than 40 minutes). Had a good look around the outside, sat in the leather passenger seats and then sat in the captains seat . The guides were very knowledgeable and friendly.
If you drive then the tour price also includes the car park (which is not cheap). There's lots more to see at the viewing park. As well as the great view of the airfield, you can also visit the Trident (free).
I hope that you have a great day.
Dave