I’ve been shooting my 26.5 exclusively this year and just bought a second. A few things that have come up.
My gun likes .180” tall front and .256” tall rear for a drive the dot sight picture. Most of ameriglo rears for the standard size Glocks are .276”, but the slimline sights are still available in .256” and fit the slide just fine.
My sample is MUCH more accurate with 124 and 115 grain bullets than 147. It’s not a POI issue, but the groups are way tighter with Speer lawman 115 and 124 +p gold dot vs American Eagle 147 or 147 HST. If you’re buying a large amount of ammo at once I’d go 124 grain based on my experience.
My first 26.5 is going back to Glock. Both of mine have the breech face cut, but the one I’ve been shooting has lost extractor tension on the case. Not sure what the issue is but I bought it new so I’m just sending it back for Glock to fix rather than troubleshooting on my own.