I used to think that, but upon further thought, a person's ears are the best instrument to level match any system to their ears. An SPL meter won't compensate for hearing loss in the right ear.
SPL meter's are best for eqing for sure, but even then verifying you like the sound signature is important. Now if you are calibrating for an event. You should use an SPL meter, but for personal viewing or even viewing with the wife who thinks it sounds no better than her computer speakers.
I've found the ears do the best job.
Personal tastes can dictate a hot center or sub.