To adjust speaker levels properly after ARC (Automated Room Correction), you need to use an external source for the test tones. Most AVR test tones are not run through the EQ filters that ARC sets. Depending on how much correction ARC has done in your room, the difference can vary from dramatic to minuscule.
That being said, there is absolutely nothing wrong with setting your speaker levels to whatever sounds best to you.
That being said, there is absolutely nothing wrong with setting your speaker levels to whatever sounds best to you.