Interesting discussion. I used to be a slide release type. But, after I was taught over the top, slingshot, that's what I use by default. Although, I've been known to use both methods. It is a gross motor skill. Mr. McPhee's discussion is academic until you've actually experienced the loss your fine motor skills when it counts. All those other fine motor skills he says you will be doing anyway won't happen. There's no aiming with sights, there's no careful trigger control. You may end up trying to to use your gun as a club, because you can't operate it.
The overhand slingshot has a better chance of surviving this loss of muscle control and engrains a common malfunction drill for when your gun stops. An empty magazine can be considered a malfunction stoppage. There is an assumption here that if the slide is back and the gun is not running then it's empty. What if you have a double feed or failure to eject? What does that look like? Will you notice the difference? Will a mag change and slide release clear that? Not likely. Will that require you to stop, rethink and change actions? An overhand slingshot, by nature, might clear the stoppage and a repeated cycling and wrist twist ups those odds. I've been known to over-hand hold on to a slide and force cycle it a couple of times to clear a stoppage. The grip is the same, so it's a good default action.
I personally have also experienced guns/magazines for whatever reason make it very difficult to directly release the slide lock. Big muscles involved in an overhand slingshot vs a thumb.
It is slower, but more positive. Yes, if you're against a clock, a direct slide release will be faster if it's only a mag change. If I'm against a BG and my gun stops running, I'm not standing in the open changing mags or diagnosing a stoppage, hoping I'm so d@mn fast at it that the BG won't get a shot.
Just my personal perspective. YMMV