Strictly answering your question, in my experience, green lasers are without question faster than any other sighting system.
Last year I started taking low light defensive handgun classes for the first time. They were real eye-openers for me and my preconceived notions going in.
First, I quickly found out that the ambient light could be low enough to have a hard time properly aligning my stock three-dot sights, but still have enough light to be able to see and identify my target(s). The following week I ordered a set of tritium night sights, and found that the I-Dot two-dot system was much easier and faster for me to see and line up. This proved out at my next low light class.
I find 3-dot sights almost useless. I've begun using the Big Dot system and find it much easier, especially when I can't focus clearly on the front sight. I can still quickly get a good enough picture, in good lighting, to get good hits on a center-mass target.
That said, in anything other than very good ambient light, even those sights are not that easy to pick up and align on the move. The bright tritium vials in the sights really don't become visible until you're in near total darkness, and they're tiny. The rest of the sight isn't terribly visible in dim lighting either. Thus, for a very large majority of cases, I find iron night sights to still not be that easy to acquire vs. any of the electronic options.
After putting a green laser on my gun with the XS sights, I found a few things that echo your experience:
1. In very bright sunlight, I could still see the green dot pretty well out to almost 21 feet.
2. In that same sunlight, I can pick up the irons MUCH faster because they're so well lit and that big dot is a BIG WHITE DOT in good lighting.
3. In any lighting scenario in which the front sight is becoming harder to quickly find, the green laser shows up very well.
4. In rapid target transitions, shooting on the move, etc. the bouncing of the dot was not distracting to me at all -- in fact less distracting than the bouncing of iron sights. So in transitions I was much quicker and more accurate.
Second, those that had some type of red-dot on occasion had difficulty transitioning from one target to the next, or had issues reacquiring their red dot after a tactical/combat reload. These were fairly well-trained shooters so none of them took longer than an extra second or two to locate their dots, but it was obvious to anyone watching that they had a hiccup now and then.
I fall in that category. I very rarely lose the dot anymore and have done a lot of practice with transitions and shooting while moving. My auto-adjusting Trijicon RMR handles light transitions well and the dot is easy to see in any lighting. I still, however, have three major issues:
1. As you said, every so often I have a "where the hell did it go???" moment, and have to hunt for it.
2. In one-handed shooting, or unconventional positions where little movements are amplified, losing the dot becomes almost guaranteed. Under pressure, I'm more likely to overcompensate the tiny corrections required which worsens the problem. And getting a good sight picture while lying prone, or on my side, is very difficult.
3. My auto-dimming function works almost TOO well. When I transition from a brightly lit area to a dimly lit area (coming into a doorway from outside, etc.) the dot instantly drops in brightness, but my eyes take another 10 seconds to adjust accordingly, and the dot is hard to see until that's happened.
Third, the two individuals that had lasers mounted (one red one green), had zero issues putting rounds on target, regardless of range (5 to 35 yards), nor any issues with transitioning from target to target to target.
After class I asked one of those gentlemen if I could take a run at our last drill with his laser enhanced gun. The course of fire involved 10 targets at varying ranges from 5 to 35 yards, at varying heights and sizes. The shooter was required to move parallel to the target line, and execute at least one reload. I finished my first run through with my weapon in just of 21 seconds, with 3 misses, all on the 25 and 35 steel targets.
With the gun with the laser I ran through the same course in 18 seconds and zero misses. Is one run-through by one shooter hard science? No, of course not. But it was a significant improvement.
I discovered a couple things about lasers. When you're at the range, standing still and trying to get precise hits on a paper target, the "bouncing dot" is a little distracting. When moving and shooting, everything is bouncing and the dot's movement isn't nearly as obvious. Or at least it's much easier to just ignore.
Two, you're not trying for perfectly centered hits when your 'running and gunning,' so to speak. You tend to see the dot enter the COM area, and press the trigger. You know that if you got a decent trigger press, the bullet went where the dot was.
This proved to be true when shooting at the 25 and 35 yard steel targets; as soon as the dot found steel, I pressed the trigger and was rewarded each time with a satisfying "ping." Very confidence-inspiring.
I'd say I had similar experience. After a few sessions with the laser, I kept thinking "haters gonna hate, but I kinda like this thing."
Other things I noticed about laser vs. red dots vs. night sights. With lasers there's no "where'd my dot go" issues due to improper alignment. In fact, one can make those longer shots from the hip, no sights required. With the other systems you are necessarily required to bring the gun up to your eye line and align the sights/dot with your eye before you can expect to get a good hit.
There is no such requirement with lasers. Simply look at the target and press the gun out towards it; the laser dot will tend to go where you're looking. I found that most of the time the dot found the center of the target before I had brought the gun up to my eye line. Safety requirements on the firing line prevented me from firing before I had located the sights, but if I had just skipped that part, I'm sure I could've run the course a few seconds faster.
Agreed again, from much experience now. I think red dots are the ultimate shooting tool
when you have a correct sight picture, but when you lose it, irons are probably better -- hell, I usually use the irons to reacquire the dot!
Advice I've been given, that works well, is to not get sloppy with lasers and shoot from a poor position just because you can. Bring up the gun and always train with irons, and still bring it up to eye level where a good sight picture would occur. In almost every instance you'll see the laser dot before the irons, and off you go. In those few situations (sunlight, dead battery, etc.) where the dot doesn't appear, you're still aligned and likely to get a hit.
Note: I'm not saying that lasers are the best, ultimate, do-all sight system. I'm just answering the above question staying strictly within the parameters of the question. From this admittedly limited shooter's experiences. YMMV. Just my two cents.
Two cents, and worth every penny!
For the most part, any time I'm carrying into a low-lit environment, I'm always carrying the gun with the laser. I know that in almost any indoor situation, and every dark situation, that green dot will be there.
I just have a romantic attachment to red dot sights because when I'm on my game,
I'm really on my game. Plus I prefer to carry my CZ P-07 which is where I run the RMR, and I can't find any good, "carryable" laser solution for it -- Crimson Trace Railmaster is the best I've found, but it then requires a custom holster, and adds a ton of bulk under the muzzle.