I calibrated my display using professional gear including a sensor that measure's NIT, Lumens, Color Temperature, and about 20 other variables, it took me 20+ hours I should have paid the technician the $300. Do you know what NIT is? No? then you didn't do a better job.
Mmm... And here i was, thinking that at the end of the day, it's what my eyes prefer to see on my screen that counts, in my house!! Silly me!
Seriously, some people take this stuff WAY too far, they should get out more and look at reality, where you don't need a bloody NIT, Lumens and Color temperature sensor...