Vinny--excellent point on red dot for aging shooters.
I've had cataract surgery, both eyes, and both replacement lenses were set to long distance focus. I use progressive lenses for reading and computer. But the progressives are too hard to use when shooting open sights, so I had one set of glasses set up for just the right focal length for a front sight, two handed grip. I used that in IDPA for a couple of years.
When I switched to red dots, I always had to view the dot with the very top portion of the progressive lenses I had at the time, but computer and reading were perfect. It always bugged me that I was having vision inconsistencies. Late last year I got another check up and another set of lenses, this time with more range at the top of the lens which gave me a much more lens area to work with when viewing the red dot without having to look through just the top 1/4" of the lens. But I had trouble at computer screen and reading distances, so I had to get a second pair of "office" lenses that I use when at my desk or shop.
I should have been quicker to address my original problem with the red dot versus how my particular corrective lens power range was spanned. Everything is a compromise. Now my only problem is having to remember to switch glasses before going outside or driving. I can use my normal corrections for the all the non-iron sights now, but still fall back on the fixed power lenses for the iron sights.
The red dot also eliminates the advantages of a long barrel over a short one due to eliminating the sight radius advantage. The short barrel will result in a lower muzzle velocity, but that is the only difference, assuming equal lock up. My P-10S results pretty much confirm this. If I ever tried run and gun again, it would be with a 3.5-4.0" barrel pistol, not a full size, with a red dot.
My opinion is that aging shooters who can see well at distance can benefit from a red dot, especially if they have problems focusing on an iron front sight distance. Point well made, Vinny.
Joe