I rarely turn my adjustable scope (20-60) above 25X or so. Usually I leave it all the way down at 20. Brighter, more eye relief, wider field. Trying to find bullet holes at 200 I usually find it gets harder if I turn the power up unless it's very bright out.
I've got a pretty cheap scope though. Barska. Unfortunately I've had a chance to look through a lot of other shooters' scopes. Konus, Kowa, Nikon, Leupold, Swarovski (drool) etc etc. You do get much better scopes for the money but WOW do they cost.