Niven used it in his Ringworld series. The rotational speed of the Ringworld was the launch speed for a ramscoop vessel.
I like the idea of finding your fuel in space. It solves many problems.
It doesn't get you faster than light, but you have to start somwhere.
Lightsails may be more likely. Especially if we change to a design based on sending laser energy from very near the sun.
Inherent in that design is the concept of slowing your speed at the end of your journey with something akin to a parachute. At least somewhere, you can slow down.
My preference at the moment is ionic drive. With the ions accelerated to within a gnat's whisker of the speed of light, you'd get "more bang for the buck." Still takes a lot of reaction fuel.
Have you read The Mote In God's Eye"? It's where I recall reading about lasers and light sails together the first time.