I have also started to explore building my own amps. They are also building preamps, and accommodations for subwoofers. Mostly just wanting to know.
Maybe I just "think" I have great sound. Now if someone were to ask me how, it would be nice to be able to explain to them how I did it, or what exactly I was trying to do.
As far as graphic EQ, it's actually pretty convenient if you are sourcing from a computer. Tweeters a bit too bright, or dull, subtle adjustments at the graphic EQ can remedy such things, even from one recording to the next. I can understand an auto feature giving a general room correction, but does this happen continuously, and for all kinds of music?
Here is my current general setting for Jazz fusion, which is mostly well recorded. Some of the more horn heavy cuts, I may adjust the highs down a tad. While with some older, classic or hard rock, the mid range bands may get some work. These are not drastic adjustments. Ideally, I would like to incorporate a hardware version of graphic EQ with more bands.