The stainless steel guide rod has no real benefit as far as weight is concerned. If you're looking to reduce muzzle climb, go with the tungsten. That being said, if you shoot any kind of competition, make sure the mode is legal in that sport. If you're a reloader, make sure your loads will be hot enough to work the 20lbs spring, factory is 17lbs according to Wolff.
Let us know how it works out for you.