I hunted with 2.5x and 4x scopes for years. In that time, I never wanted LESS power and only twice did I want more.
The first was a pan-sized hog that I shot at about 10:00 PM with a Nightforce 3-10 SHV set at 5x. The second was a smallish black bear that I killed at 353 yards with the same scope set at 10x. Those are the only two shots I can think of where a 2.5x or 4x would NOT have worked as well as anything else.
Okie John