Here's another LEO weighing in:
My perspective is this: A cop needs to know how to shoot, operate, clean, and maintain his/her weapon. This is coming from me, a cop who has been shooting since the age of 5. I know more about my weapons than a lot of guys in my department, simply because it is a hobby for me (in addition to a piece of safety equipment).
Nevertheless, whether or not the LEO realizes that the ambi-safety is an upgrade (rather than a standard feature) is virtually irrelevant. Knowing every intricate detail about the ammo is also not necessary (do we really care how many grains of powder push the JHP bullet towards the target? No, we care that it gets there). Certainly an operational knowledge of the weapon is important, but this doesn't mean that the officer needs to be a qualified armorer to carry the gun (I drive the Crown Vic at work, but I'm certainly no mechanic).
Now, obviously there are some fellow officers that make us all sick with their lack of knowledge about their firearm(s). I went to qualify one day with one of my shift partners (he has been on the job for two years). He did not know how to disassemble his weapon for cleaning (a Glock), and needed the range staff to show him how! That is a bit appalling, and demonstrates a basic lack of knowledge regarding that tool.
But, just because an officer doesn't know what features constitute a "loaded" 1911, doesn't mean they aren't capable of operating the weapon in a tactical environment.
Honestly, I can't recall with certainty what grain bullet my duty weapon is carrying currently. We are issued the ammo out-of-box, and I can't recall what I was told three years ago when we switched to that ammo. I know that it is a Speer Gold Dot JHP bullet, but the grain weight of the bullet is irrelevant... It doesn't matter because I don't have a choice of using anything different anyway!!! I shoot this bullet often, and I know where it lands on the target (and that is important).
My own personal firearms are a bit different. I can tell you what is in my own firearms, because I buy and choose that ammo myself (ie: 165gr Speer Gold Dot in my .40S&W Glock).
Does all of this mean I am unqualified to carry my firearm? I think not, and my qualification scores would support my view on this.
(for the record I'm nearly positive that I am carrying a 200gr bullet in my duty weapon... But, again, what difference does it make to me when it is the only "choice" I have?)
I should also add that I know far less about the lightbar on the top of my marked unit than I do my firearms, but I still feel qualified to operate that piece of equipment... One of the guys on my shift is something of an armchair lightbar expert, and is always talking about the various features and visibility of any given brand/model of lightbars. I couldn't care less about that topic, simply because I (once again) have no say in the matter. I get the lightbar they give me, and I live with it. Lightbars are not my hobby, even though they are important pieces of safety equipment, so I really just live with what I have.