Is there any reason NOT to update devices that topped out on iOS 15 to the latest 15.8.7 update, and then JB with the updated Dopamine

I’ve got a few devices that max out on iOS 15, and since opa344 gave us an update to Dopamine, I was curious if there’s any reason to not update for the official security patch on the old hardware.

Like is there a performance hit between 15.4.1 and 15.8.7? Or does the updated Dopamine suck?