I use it all the time, create "Sink The Marat!" in CLOD to learn the stuka (It is way harder now, I think the airbrake is way worse in the CLoD stuka), learn to fly planes, check out ground units, practice strategies.
It is really quick and easy to use, basically:
View object, find the object you want, click it, CTRL click somewhere on the map (this spawns the object).
If the object is a plane: Group properties to pick its side, number of units (you could have a whole flight under one "dot") fuel load, payload etc. Then you will see in the view object browser for that unit a list of numbers up the top, these are individual planes. Select the one you want and check the box that says player piloted or somesuch.
That's just from memory so watch out for the gratuitous amount of errors
