The Nighthawk is a very good knife, price aside, and a great value for the money. Everything about the knife works well - the handle, the blade, the sheath. A very well thought out knife in terms of design and construction. As to the steel, mine(1995) is 425M, but I believe the Nighthawks made for the SEAL competition were in ats-34, and the steel changed to 425M for the mass market version to keep the price down. I removed the black coating on my Nighthawk, and it didn't come of too easily, so I would say that the coating is pretty tough.
As to the Camillus kabar, it looks like a nice enough knife, and if you bought one you'd have a good knife, but I would prefer the more refined design of the Nighthawk over the Camillus.