It'll be great if we could see a pop-up balloon (or yellow sticky note) description when we hover our mouse cursor over a folder or file in Xplorer. This is possible in Windows Explorer but doesn't seem to be available in Xplorer.
I have drawn an illustration with Photoshop to help visualize my suggestion. Please take a look.
i don't know how explorer does that so that's why it's left out
but you can set x2 to calculate folder sizes using the relevant advanced option (quite resource-intensive, has to be said)