Sonance, Those graphs and measurments are absolutely worthless. The finest measuring gear ever made is on the sides of your head. This is what "The Absolute Sound" used to be about (say in the 1980's). They would plug a piece of gear into their reference system and LISTEN to it for a month. Then they would tell you what they heard. That's all that matters - does it sound like music? They were credible because thay had a reference and replaced one component at a time for extended listening and didn't get bogged down in the specs. The specs don't really matter.
If you try, to the extent you are able, to emulate that methodology, you don't need no stinking graphs and you'll develope a great ear also.