The reason to get the TW-1 is due to precision. The TW-2 covers more range but it looks like the increments are in 5 N-m tick marks, and they're rather small. It will be hard to measure something like 7 N-m accurately. That's my only complaint with the TW-1, to really make it useful it should have gone to 10 N-m or 15 N-m. As it stands a lot of the smaller bolts call for a torque just above 7 N-m (10-15 N-m, for instance).