Fully agree with 1-2-3-4. on top of those..(my take)
XC60 has bigger trunk and larger leg rooms. cabin noise level is lower.
X3 is a better driver, and therefore demands you to "drive" it. i.e not a relax cruiser as, e.g MB, or Volvo to a lesser extent. Engine note is higher, but some people like it as sports car flavor..and more expensive to maintain after warranty expires (last one is from a 5 time BMW owner)
Q5 pricing might be a bit higher. In my case, if I want rear view camera, then I need to get at least Premium Plus trim, then I could have "option" of buying a $3500 navigation package for the rear view camera...
Volvo has tailgate package for the camera for $1300 MSRP starting with basic trim.
I also chose XC60 T6.