I thought he meant the speed would be about the same but a "better angle" meaning a deeper angle with the spinnaker. If you want to make a non-spin cat go fast downwind, you have to go much higher and gybe a lot more, covering more distance. The spin cats can go "the same speed" ie. fast, but deep, ie. "a better angle" to C mark.
Now, you could just turn dead downwind with a Hobie 16, non-spin, and cruise straight to the C mark, much less distance to cover, but you will be going slowly. Usually it pays to head it up, get it going faster, bear off in the gusts, gybe, repeat. It depends on how much wind you have, etc.