Retention holsters seem like a good idea. They keep the gun locked in place—avoiding embarrassing episodes of Skittering Gun Syndrome (a.k.a. negligent brandishing). They also prevent unauthorized personnel from withdrawing your weapon and using it against you.
The primary consideration for a holster is its ability to enable a rapid, secure draw on target. In a gunfight, the person who gets the first shot (or shots) on target generally wins.
In other words, the sooner you shoot someone in a place where it does some good/bad, the sooner you stop your aggressor from shooting, stabbing, assaulting and/or maiming you or someone you’re trying to protect.
Bonus! As around half of all lethal threats involve more than one attacker, the sooner you shoot one antagonist, the sooner you can shoot another. And another. I think I’m trying to say that speed is of the essence.
So is simplicity. The easier it is to get that initial shot or shots off, the more likely you are to do so. ‘Cause gunfighting skills tend to go to shit in an emergency. A holster retention button you used a thousand times in practice (hopefully) can suddenly turn into a Gordian knot. That’s not good.
[NB: It’s the same logic that leads to the conclusion that external safeties are a bad idea for a combat gun. Hence the reason they don’t have them.]
Also, shit happens. You need all the mental bandwidth you can muster to maintain situational awareness. IF the retention button is a problem, it will slow you down mentally and ratchet up Force disturbing fear and anxiety.
Another thing: you should withdraw your weapon from the holster with your trigger finger as high as possible on the gun (e.g. on the barrel). I know of no retention holster where the release button is positioned high enough to allow you to put your trigger finger where thoughtful gun gurus (e.g. the rabbi) believe it oughta be.
Cops need retention holsters. They’re authority figures who open carry all the time. Their guns are an obvious target for violent people whose tenuous grip on reality is further loosened by regular infusions of mind and body-numbing chemicals. To reverse quote Christine O’Donnell, they’re not you.
For you, the danger of losing your weapon to an attacker is smaller than the danger of not being able to fire your gun quickly and accurately enough to win a gunfight. And once you recognize the danger of losing your gun, understanding that you need an inviolable “bubble” around your gun, the risk decreases further still. Avoid open carry, and you can round it down to zero. And use a non-retention holster.