I have a New Agent and figured out that the "trough" was more or less useless to me, most likely because of my long ingrained need to see a sight picture when aiming a pistol.
I practiced a lot at short range trying to get the hang of Colt's intentions using the supplied 'aiming guide' but I kept shooting low whenever I tried to work up some speed. I joked and called it a great pistol for shooting short bad guys, or my kneecap blaster.
But then one day I realized that I didn't need to aim the pistol at all, at least not in the usual sense. If I concentrate on my intended point of impact and let my arm/hand point naturally there as if I had no pistol, release the shot as my pointing came to where I was looking the shot hit where I looked or close to it. It was a return to a Zen experience, something I hadn't practiced since giving up martial arts years ago.
I continued to practice this way - something like leading ducks on the fly with a shotgun, another sport I hadn't engaged in in many years, and I remembered a technique taught to me and all of us young troopers in basic training in 1967.
The army called it "Quick Kill" at the time and it was taught us with Daisy b-b guns. I have no idea if they still train for the method but it's pretty much what you do if firing on full auto as the M16's of the day could do. We didn't have 'burst' mode.
They started us out paired off - one guy with the b-b gun the other to toss a white disc (seems like it was a 6" disc) in the air. The shooter was to swing the gun up and hit the disc on the fly. As I recall we all got good at that pretty quickly, because it sort of comes naturally. As the day progressed they switched us to a smaller disc, about 2" if I remember, and everyone got good at that even quicker than the first disc, I guess because everyone was getting the idea. Seems like the army was satisfied with the 2" disc, but most of us pulled out quarters and were hitting those easily. Then dimes, and the tosser would start trying to make it harder by throwing high, low, or at an angle away. Just about all of us were hitting dimes with just about every shot, and my buddie and I got to the point where we could each reliably hit anothe b-b tossed in the air. I know that a lot of the other guys in that platoon were hitting b-b's too, it really wasn't much harder to do than hitting the discs if we let our thinking stay out of it. I remember that part of basic as one of the most fun days I had there, although before it was over, about the fifth week I was thinking that it was all fun. I don't hear a lot of people say that they enjoyed basic training but I did, once I figured out that I was getting stronger and better from it.
So.......although for a while I did consider putting sights on my New Agent I like it fine now and think it's probably the most efficient fighting gun I own. I usually don't carry it but I have it nearby in a little kit I made up of gun and nine loaded mags. I also put a cut down rightside safety on mine and trimmed the leftside lever down almost flat because I'm a southpaw. It's not a pretty pistol but it is a deadly one if needed. I can hit with it from any pistol distance by looking, pointing and squeezing off shots, almost without giving it conscious thought.
I'm pretty sure now that this is what Colt had in mind for it's use and they gave us one of the best combat pistols or carry pistols available when they thunk it up.
And.....there's always Crimson Trace...