I have the KSC G17 with the metal slide and barrel. I also installed the G&G metal guide rod. it is one of the best GBBs I have ever owned or shot. For a simple, reliable, cost-effective sidearm, you cannot go wrong with the Glock. By the way, my G17 cycles the metal slide just fine without the use of a hi-flo valve or any other assistance.
-The Crow