Ask yourself what you'll be using it for and you might be able to use something else.
I use either my 12v Dewalt cordless drill with a socket bit and the right size socket, or my Makita 12v driver with the same setup. I do NOT use either to do the initial loosening or the final tightening of anything that's more than 5-6mm diameter (bolt size, not head size)- I use a breaker bar, torque wrench or ratchet for that task. Basically, I break the fastener loose with a hand tool, then zip it off with the cordless tool.
It really seems to make the power tools last longer, as you're not stressing them to the max by trying to break loose fasteners, and you're not hammering on them trying to get things just a little bit tighter.
I can see where a true square drive cordless impact could come in handy, but I am happy with my set up.
Rig