We have used this to screw down 5/4" cedar decking with 2 1/4" screws. I have not had any screws jam in the magazine, however if you get into to much of a hurry the screws will shoot cock-eyed out of the open side. The extension keeps me (I'm 5'6") from bending over, Until a screw dosent seat and then its hit it with the cordless. You can adjust the depth the screw seats, but you need to change magazine assemblies for differnt size ranges of screws.
I don't recall the amount of screws in a box, and the price veries as if they are galvanized or black. Other than the general keeping it clean you need to lube the shaft extension every so often.
To tell you the truth we needed one and it was on the shelf. I haven't seen the Hilti to compare it. It will shoot from 1 1/4" to 3" with 3 differnt magazines. Screws are Phillips or Square, I do not think it will shoot hex heads.
The Quick-drive comes attached to a corded dewalt screw gun, if it comes attached to another brand or cordless I couldn't tell you.
All I know is inspite of the draw backs, it still beats screwing decks by hand. DH