Several firearms trainers advocate the closed-slide speed reload. (Dropping a mag and loading when the mag is mostly depleted but rounds are still in the gun). I think it is a valid technique in specific circumstances but as with any technique it has its drawbacks. In the middle of a shooting, when the suspect and good guy are moving, looking for cover, trying to react to each others actions, dealing with the fear of potential death, etc., trying to count rounds becomes very difficult. It is well documented that many individuals involved in shootings have no idea how many rounds they fired...Some believe they fired a certain amount but it was actually many more. I recently ran an solid performing student through our shoot house. He engaged each target in the close confines of the house with five rounds, making good, solid hits. After the drill I commented how I was impressed by his decision to engage with multiple rounds rather than the old-school double-tap/assess. He said he trained and planned to shoot them each three times because two might not be enough. I said "so you shot them each three times?" He said "Yes". I said "So you didn't realize you shot each target five times?" He said he thought he shot each one three times. He admitted part of the reason he went empty when he didn't want to was because he didn't think he had fired as many rounds as he did.
Any form of "offensive reload" such as a tactical reload, reload with retention, slide-forward speed reload, etc., are almost never conducted in the middle of a gunfight... They are conducted after the shooting, or during a lull in the gunfight IF the person has significant training. The vast majority of the time the firearm will be shot until the threat has been neutralized or the weapon is out of ammunition. This has been supported by force-on-force training as well as documented shootings. If one never trains for their gun running out of ammunition they are failing to train for a very likely result of a real shooting incident...Especially if they are using a lower-capacity handgun.
The fine-motor skill issue is true, but one must remember that pulling a trigger is also a fine motor skill. Landing an airliner in the Hudson river is pretty stressful and requires all sorts of fine motor skill. This is why training is so important. One must train such that the technique-based response in a stressful situation is familiar and can be accomplished without advanced thought. Hitting the slide release is simply not that difficult when one thinks of all the things one must do in a gun fight. My department has a significant number of shootings to support these contentions.
We put sights on our guns knowing that under stress pupils dilate and close-range vision, and thus front-sight focus, becomes difficult. We overcome this problem through training and stress inoculation.
There is nothing wrong with the overhand/powerstroke loading method. It is one of the options we currently teach. In fact, I prefer the option for most shooters. I have used the slide release so many times it is automatic. I have to "think" to use the overhand method.
I just think it's funny that people buy into the idea that a manufacturer can put a device on a firearm that has been used for the same purpose for a hundred years, call it something else, and people just go along with the idea it isn't the same thing it was before.
A break pedal will apply the breaks no matter what it is called. A trigger will fire the gun no matter what it is called. If they put a lever on the gun with serrations on top to assist with downward motion and if that downward motion releases the slide it is, by definition, a slide release... No matter what it is called.