Room correction room system vs ears….

So, I splashed out and spent more than I wanted to on a nice little Benchmark amp and preamp etc and since I’ve gone that far I got curious about a room correction system for this and it’s going to cost me over a grand apparently. As far as I can gather these dial in the music before it comes out of the speakers…?

im wondering if I simply messed around and found the sweet spot without a room correction system how much of a difference this would make. I’m far from savvy with audio and try to keep things simple for my simple brain, so, on a scale of 1-10 how much difference would I percieve by splashing out on a room correction system?