Unless you are in a Infantry unit an going overseas soon don't count on getting one. Well, I dunno if other combat arms units get it. I think it's just supposed to be for units that would/could do dismounted ops.
I got it, its pretty much like a giant small pack. It's not bad, the frame/stays that you bend to form to your back is kinda cool.. but be useless when wearing armour an I can see them bending/breaking if you drop them or something.
You get the ruck, two large pouches you can attach to it and a compression sack for your sleeping bag. My ruck is empty right now, so you don't really get too see how big it actually is. The ruck an its componets come in different sizes; so before you get issued it you get all sized up an they get you the parts that will fit your body better.