If you did it right you should hear deeper into the recording, more detail but in a smoother more natural way that may not be all that obvious at first, and this realistic smooth coherent sound will only become more natural and organic as the hours add up. That's a real good cap swap when you get that.
There are only two times anyone should be talking about tone controls with caps: in crossovers where the value does directly affect response, and when the listener isn't able to appreciate that the areas described above got better, instead noticing only the lack of grain and glare, which they misattribute to being toned down. Since you went the extra mile to check with the designer then you are quite correct to dismiss the poor listener and his misinformed tone control comment. If yer gonna mod, do it right- which includes knowing what to question and what to stand up for. Which you did. Well done.
