Everything. Sooth, fast good engagement, and you have the guarantee of a Profile product!
Kinda pricey, but I'd say it's worth it.
The hub is fast, sooth, great engagement, look good (especially in purple ), and the sound is pretty nice to boot. You also can just buy replacement bearings, pawls, springs, etc. so you don't need to buy a whole new hub if part of it decides to stop working. It is kinda pricey, but, I would definitely say it's worth every penny!