I bought a calibrated set of Stormy Mondays and they were in superb balance with each other at about the same height. When using a stock set of Gibson uncalibrated pickups, the bridge p/u had to be way up and the neck p/u way down.
It's like getting balanced pairs or quads of valves for your amp, you need two horses that pull together across the beam.
Mine were 7.2K and 7.8K impedance and they balanced perfectly. The extra 0.6K of windings on the bridge p/u compensated for the smaller string vibrations at that point. I would always go the 'matched pair' route.
:D