Good stuff. Thanks, chevy82 & Mike.
These are right in my price range. I like that they're two separate drivers and include two batteries. The Porter Cable impact is rated at 1450 in-lbs (120 ft-lbs..?) - that should hold up well enough to change a wheel & tire, eh? That'* nearly twice the torque of the other two - this may be a deciding factor here.
Thanks again to both of you!