I pest and hunt small game up to rabbit size in a rural area. I live on 10 acres but there are a number of houses within slug range and there is a high likelihood that people will be out riding bikes or walking the dog. The fact that pellets loose their energy faster and have a shorter range is a benefit rather than a liability.
My thinking is this...
How far away can you spot a bird, rabbit or squirrel?
How far away can you consistently hit the 1 inch kill-zone on the animal?
How much energy do you need to dispatch the animal?
How much energy is wasted/not needed after the projectile passes through the animal?
You may be a better shot but for me, under my typical conditions, 50-60 yards is my practical limit and a 30-33 fpe, .22 caliber PCP shooting pellets will do the job just fine. I can consistently hit where I want/need to don't need to compensate for inaccuracies with excessive power. I don't need/want more energy or range.
As far as .22 caliber power goes, 30-33 fpe (16-18 grain pellets) is typical and practical for most mainstream PCPs (like my Air Arms, Daystate, Feinwerkbau, FX and Weihrauch rifles) giving reasonable shot-counts.
To up the .22 caliber power I use my Impact with 25 grain JSBs tuned to around 50 fpe. At this power level the Impact has no problem dispatching groundhogs, raccoons or porcupines.
For more .22 caliber power my Panthera is (currently) shooting 34 grain slugs at just over 60 fpe. I've killed two coyotes (at about 50 yards) with this setup. When I'm done testing slugs, the Panthera will get a new liner and be tuned to shoot pellets.
Slugs have a "cool factor" but from the economical perspective, pellets are a lot cheaper (cost and air) so I can shoot more, they have proven they are effective and (repeatedly) demonstrated that they are more accurate than slugs within their effective range. Yeah, slugs have a better BC and don't drift as much in the wind but that really is a benefit at longer than the ranges I typically shoot at.
In my comment to the OP, I prefer .22 caliber for the reasons listed above. If I was typically shooting larger, tougher pests (groundhogs) or animals like ground squirrels at longer ranges the I'd definitely go to .25 or larger.
As a side bar, I did hunt squirrels with slugs and my Panthera last fall. The young lads who have permission to hunt on my property had the squirrels spooked to the point that you couldn't get within 60 yards of them. I setup a chair and rest in the hardwood bush and took 18 squirrels that season - all head-shots, all on the ground with a safe backstop - at between 60 and 80 yards.
View attachment 458063 My thought is: Don't underestimate the power of modern .22 caliber PCPs. Each to their own eh?
Cheers!