The MPS is my dive knife. The plain edge is fairly sharp and the serations are wicked sharp. I've used this on a number of dives and the only corrosion I've seen has been on the metal rivets used in the kydex sheath. The removable handle slabs don't add too much weight and really provide a good firm grip on the knife. I've never rinsed this knife off and I'll never have to.
I can't really compare it to the CRK's or Busses in that they are different beasts entirely. I won't beat on the MPS the way I do with my Busses in the woods and it isn't the same as the CRK's as far as finish, balance, etc.