Almost nothing is shot in IMAX. Now they have the new IMAX cameras and will be using them for Civil/Infinity Wars, but Christopher Nolan was just about the only one I know of who was actually using an IMAX camera and only in some scenes of TDK and TDKR, but they were very difficult to use. Some of the shots in true IMAX are, however, breathtaking. (EDIT: Should have included Interstellar).
Go see it in IMAX if you like the franchise. It's worth it. That jet takeoff trailer is still blowing my frelling mind......
EDIT: As I understand it, the Russos are using the new 2D IMAX camera for some of Civil War and using it exclusively in Infinity Wars and doing a 3D conversion. I wish they'd just use the new 3D IMAX camera and skip to conversion. They are getting pretty good at the conversion, but I don't believe it's as good as shooting in 3D (Hugo being a stunning example of 3D work). I'm sure there is a downside (expense, knowledge of how to use the cameras correctly??), but don't know for sure what it is.
Is there an expert out there on this subject?