As with every thing I did find pros and cons to both machines. The Tormach has a faster spindle speed (400rpm faster). And might be more ridged but it is a smaller machine. It uses steppers instead of servos and has less torque in the X and Y movement. And has a max of 65ipm instead of 100ipm. The IH has a gear drive spindle with might make it louder but has more torque. I haven't found much on the table extensions and what they do. As far as the closed loupe or open loupe encoders. I haven't found out what is what. I do see on his conversion kit it comes with encoders like you would use on a DRO.