Snapper, of course the IR111 "knucklesaver" is an entirely different kind of tool, combining ratchet and impact action, while the moving parts and operation of the IR107XP is the same as most ratchets. The old common cheaper ratchets have the exhaust to the front on the bottom, while the 107XP exhausts to the side and you can turn it to whichever direction you want it to go (it's almost identical to Snap-On's top of the line ratchet). The 111 exhausts to the rear. They're both rated at the same torque (50 ft./lbs.) and they're both fine tools. My personal preference would be the IR111, but they ain't cheap.
You know the 111 replaced the 110 that isn't made anymore. The 110 was just a little more powerful, but I was told that the extra power caused them to wear out head kits faster so they reduced the torque a little. At customers' requests, I upped the torque on a couple of 111s simply by drilling the exhaust holes in the cylinder a tiny bit larger, but I don't recommend doing that since they do have as much torque already as most ratchets.
Of course I was working on tools for professional mechanics who used those tools daily (and sometimes neglected to oil them daily). If you're buying for personal use, and give them a little shot of air tool oil in the air intake each time after you use them before putting them away, they'll last you a lifetime.