Returning to a Glock after several years. Would like to know 1. I read Gen 5 is VERY different from prior gen 4 and 3. Want to order night sights. Does Gen 5 require sights specific to Gen 5? 2. Is the rail a 1913 Piccatinny rail? 3. Do they require hot loads to cycle reliably (assuming a proper hold). Thank you for your time!