I just recently purchased a g21sf and am on the fence regarding a few desireable BUT not mandatory upgrades. I would like to get feedback from individuals that have experience w/ both of these items to help me make a more informed decision. Mod 1: Extended Slide Lock (release) Do I go with the Glock brand with just the extra triangular nub or the Arotek? Is the Arotek worth twice the price of the glock branded stop? Mod 2: upgraded guide rod Do I go SS or tungsten? Is the tungsten worth twice the price of the SS? Mod 3: upgraded trigger connector and springs Is a Scherer 3.5 trigger connector paired with glockworx competition spring kit a good idea for a bedside bump in the night gun? Thank-you for all the input and advice.