Most Accurate KW Research Tool

Hi all,

Just curious, in your experience, what is the best and most accurate research tool? I was about to begin a campaign and noticed a pretty big discrepancy on some keywords with ahrefs and kwfinder. With one of them, ahrefs was showing the keyword score of 64 while kwfinder was giving the same kw as 34. Huge difference. Which one is more accurate? Are there other tools which are better?

Thanks!

https://www.blackhatworld.com/seo/keyword-difficulties.1229535/, still applies mate.