Meters certainly can do better. Calibrating by ear is inherently inaccurate. By using a meter, you can match the levels to within a couple of dB - at which point, your system will be reproducing soundtracks at the levels that the sound engineer and director originally intended. I've exchanged posts with more than one person who was unsatisfied with their surround system's sound and blamed their hardware, only for them to subsequently calibrate with a meter instead of by ear and discover that the system was transformed as a result.

Calibrating subs still is often a bit of a "tweaking" process - the commercially-available meters tend to be less accurate at the very low frequencies, and many people prefer to run their subs "hot" by several dB for the extra effect that provides.