A touch of brightness

[Antoine]

Without measurements we can't be sure what's changed and how/how much and whether it's enough. But in any case I think your brain has to "decompensate" after getting used to a certain type of sound for years, so I'd give it some time. Also you may have to do/re-do some fine tuning of your system like loudspeaker placement/amount of toe-in etc. There's no doubt in my mind you're now hearing more of the intended sound and less of the room induced sound.

Now that you have effective panels you could also start experimenting with their locations, perhaps not for definitive placement or for these exact panels but at least to learn how they can work out/influence the sound in these different locations. It could as well be that these thick panels provide too much absorption in this location so close to your ears and tilt the balance to the unnatural. I don't think they're too much for your room it may just be their location. (to give you an idea I know I have near to 40m^2 of absorbing panels (Rockfon Sonar D acoustic tiles) in my room, all on the ceiling and a very heavy 2,5x2m wool rug on the floor in my seating position but reverberation times are still a little bit too high (shown in measurements), there's also still some flutter echo between my parallel walls)