Those are two very good differentials. I run a Torsen in my Lightning and love it. Have not been to the strip with it yet, but on the street and coming out of hard corners, it definately hooks up.....awesome. Since it is clutchless (some sort of gear drive), the wear rate over time is VERY slow, so you get great performance for a long time.
The Eaton is also a very durable unit and performs well for a lot of Lightning guys I know on the drag strip. Not sure though how it does coming out of tight corners. It is a speed differentiating unit, so you will see some slip or wheel spin before it kicks in. (I haven't seen that with my Torsen, which is a torque differentiating.)
Bottom line - Both are good, probably won't go wrong with either. But I reeeeeeeealllllllllly like the Torsen in my truck!
Have fun,
- Kevin