I have one installed on my 21SF. There are some very good arguments for and against the Siderlock. It's also one more thing for anyone who shouldn't have your gun in their possession figure out how to circumvent. If an intruder finds your gun or even if you carry and get disarmed this adds potential life saving seconds if you find yourself on the wrong end of your own gun. Perhaps that sounds like quite a stetch of the imagination. I like it and run drills at the range using it every time I shoot. To each his own.
NRA / ISRA MEMBER / LOCAL 701 MEMBER
Glock 21SF, FNH FNP-45 S&W 686, Taurus PT1911SS, CZ 75 SP-01 Tactical 9mm, Browning Buck Mark Stainless Camper, Ruger Mini-14, Mossberg 500C 20 Ga.