The Scimitars are a smoother riding fin. As you know, they curve every-which-way.
The constant curve curve seems to be what makes them smooth. According to Futures, they have an increasing cant from 6, to 9, to 18 degrees.
The 3/2/1 hve this same increasing cant angle, but the angles are 6 to 9 to 11...so that final angle is "somewhat" more upright - if you can call 11 degrees upright.
The cants, though, are straight. This crude drawing shows what the cant looks like between the two fins.