I have recently been comparing and considering making the move to flac .. then I heard them and realised the same as you. I only really needed to upgrade my old mp3s I made a decade or two ago to 320kbps.
Perhaps if you have a mega sound system that can really push out the extra detail out of the sound then its worth the extra space/effort to convert everything, but on my Audioengine A5+ with DAC I hear no difference at all .. and I mean no difference!
But anyways ... getting off topic .. Music player would be cool