How close do you shoot?
A red dot is usually set at 100 yards, and parallax will make it tough to make a group at close range. You will have to carefully center the dot in the glass to get repeatability. That defeats half the purpose. You will still get fast target acquisition, at least. Bullseye shooters use them, but they are shooting at 50 yards. Action pistol shooters use them, but 3" groups are good in that game. I have tried a red dot on an air pistol, and it was pretty hopeless, IMO. With a rifle, sure. You get a cheekweld, at least.
Most pistol scopes are also fixed at 50 or 100 yards, but at least with a pistol scope you already have to center the hairs pretty close, else you won't see anything, at all. And you get magnification. But the downside is with a fixed AO, you probably won't be able to get a clear focus inside of 7-8 yards, and the higher the magnification, the bigger the problem. And at close range, you will get some blurring of the crosshairs when you focus on the target. In some lighting conditions, you might get into situations where the hairs "disappear" on you at shorter ranges.
I bought a 4x for a pneumatic pistol just to check pellet groupings. But after I took it off, I realized how useful it is. I can just about hit my own pellet holes at 10 yards, with an impromptu rest. (And I don't have to get up to see the holes!) I put the scope back on to stay. I have two of those pistols, anyway. Mine is a Simmons Pro Hunter, but I have no idea if it would hold up to a springer. Parallax is fixed at 100 yards, but it hasn't been a significant problem as long as the target is farther than 15 feet. BTW, the difference between 50 and 100 yard parallax is pretty tiny. The difference between 10 yards and 15 yards is probably 3-4 times as much. So the difference between a 50 yd scope and a 100 yd scope is almost moot. They're going to be almost equally off at 10 yards. And the point where a 4x scope starts to blur significantly might be different by a foot or two. But the 100 yard scope makes a better telescope.
For an air pistol in general, and for pests farther than 15 feet in particular, I would probably want a scope. Close doesn't count with a single shot airgun. I would look into a Crosman Centerpoint 2x20 scope, maybe. Their rifle scopes are all spring gun rated. Maybe give them a call.
My eyes are getting bad enough that the fixed sights don't work very well anymore.
I might be too old, myself. But I could never shoot those fiberoptic sights well to begin with.