The Topre Type S has slightly less key travel vs. the standard Topre switch.
However, that slightly less key travel translates into a significantly different typing experience.
Comparing my standard HH Professional 2 with my HH Professional 2 Type S, I definitely prefer the Type S.
Not only is it quiter, it is also slightly more enjoyable to type on. I am able to type about 5-10 WPM faster on the Type S, even faster than on the IBM PC AT 84-key Model F.
So IMO, the HHKB Pro 2 (not an inexpensive proposition to begin with) was made even better with the new Topre Type S keyswitch.
Whether or not it's worth the $200 premium is entirely subjective.
For keyboard connoisseurs who can appreciate the subtle differences and afford the premium, the answer is Yes!