The Sentinel is both sealed against debris and has a thick probably non-snapping mid length piston at a similar price point to the WK Gen 2. It will be interesting to see if people will overlook the looks to go with the Sentinel's robust design. I myself think it looks great for Larping Halo or Starship Troopers during a match, plus the monolithic upper looks strong enough a Gears of War-style chainsaw bayonet may be possible 