The problem with comparing the TS 75 and Festool TS 55 is the two saws have nothing in common aside from the fact they share a similar appearance.
The TS 55 is build for weight. There's a lot of quality compromises made get the weight down below 10 lbs.
The TS 75, like the Dewalt is a beast. It's close to 15 lbs. The build quality of the TS 75 is vastly superior to the clunkier TS 55.
I love to make pretty things for pretty little things