I think if you mainly shoot under a hundred yards, and that would be the vast majority of Airgunner, pellets get the job done, and done more easily and more accurately. Most high end airguns were designed to shoot pellets, so no experimentation required nor desired. Buy a tin of JSB and off you go.
When you decide to go further than 100 yards is where the benefits come in with higher BC and therefore better wind performance. On a calm day, only slight benefit. Last summer on two consecutive weekends I connected with ground squirrels at 200 yards with .30 JSB pellets. But it was early morning and very calm. Any wind at all and I wouldn’t have even taken the shot.
Yes, I know there are videos of guys with their Impact “mortar” gun’s shooting 250 even 300+ yards and occasionally hitting their target, and that’s pretty cool. Nothing like a 15 foot holdover at your target to get the blood pumping. The only way to reliably do this is with slugs... And it is fun, setting up your shooting table, rest, bags, canopy, cooler, stereo, refreshments and all that. Its a social thing that looks like an entertaining day... and it’s one version of “pesting”... Not my usual hunting or pesting style, but whatever floats your boat.
As far as cost, with Nielsen at 275 slugs for $19 in .25 caliber, they are cheaper than .30 caliber pellets...