I've been meaning to start a post on this unit for a while...
http://www.matcotools.com/Catalog/toolcatalog.jsp?cattype=T&cat=2348&page=3왓
It's worth every penny.
For reference, I was previously using a 12V Makita:
It lives at home now, and I use the Matco at work. For a 3/8" electric gun, it's a monster. If you actually torque the lugnuts to spec, it'll remove them easily. Once you've dropped the subframe out of a car (you'll need an air impact for the suspension and subframe bolts) you can swap an entire engine out with this thing.
I now routinely install upper engine mounts without ever having to grab an air hose. The Makita wasn't nearly powerful enough for this task.
I'd say (with a fresh battery) that the 100 ft/lbs rating is pretty accurate. Like I said, it'll baaaarely remove a lugnut torqued to a 90 ft/lb spec. It has to rap on it for about 2 seconds to do it. But that's a huge improvement over the Makita, which was only good for about 30 pounds of torque.
The Matco weighs about the same amount as an average 14.4V cordless drill. I's not too bad.