I would echo my dissatisfaction with the Cat Eye.

However, on given day with "stable" air, it will repeat a given measurement....

Can anyone explain the relationship of air pressure to a given altitude setting?

For instance: at sea level, how much altitude deviation would there be with the atmosphere at 28.5 or 32.5 millibars?

Would the differences be amplified at higher elevation?

current pressure is 30.0millibars against known altitude of 5,000ft.
what happens if it changes to 28.0 or 32.0

Is the deviation larger at higher altitude...?