2) The assignable 'shift' button function works across controllers, e.g. assign shift to a pinky button on the stick or throttle, and then you have all other buttons on the stick & throttle available for shifted functions
3) Mode switching. CH Control Manager allows you to define actions for 3 different modes and then switch them with one global button on the stick or throttle (with corresponding green/red/amber light), so one button press and your whole config can be changed across all CH devices. I love this feature so much and make extensive use of the 3 different modes, which I use for 1) general flying, 2) combat, and 3) exploration / Supercruise / forum browsing (alt-tab on thumb hat/trigger ftw)
If you're the sort of person that likes to tinker you may also like the fact that the CH software allows you to program all the devices, buttons, and axes via scripting. You can also control what scripts execute based on which of the modes you are in. For instance, I have a normal throttle profile for general flying, a scaled profile for combat where 50% of the throttle throw is in the blue zone (instead of the normal 20%), and a stepped profile for exploration and Supercruise with increments of 0, 25, 50, 75 and 100%. I don't know of any other products where you can do that kind of crazy stuff
Hope that helps.