I went with 5/8” MDF.
MDF is a very good choice for cabinets and panels, for all of the reasons you note. 5/8" is good to keep weight down, but may not be as easy to find as 3/4".
Some tips I have found while using the stuff:
ALWAYS wear a dust mask. The dust generated is very fine and it's very bad for you.
Cover anything in the room you don't want to get coated with dust. It goes everywhere.
Seal all of the surfaces and edges with at least two coats of a quality sealer, such as Kilz primer, and sand between coats. This is especially important if it's going someplace where it will be damp.
Never screw directly into the edges of the stuff. If you must make an edge connection, consider using the special cabinet hardware one usually sees supplied with ready-to-assemble furniture. Even with special hardware, you never want to make an edge connection on any panel which needs to bear any significant load. MDF is very weak in that direction, and will split easily. Always better to use a framework, or blocks, and screw directly in the face of the panels.
Consider using edge or corner protectors on any panel likely to get banged around, particularly the bottom. Little is more heartbreaking than having a corner break off (and it will) when you accidentally bang your freshly built project on something while moving it into it's final resting place.
RandyT