Hey KK..........Mimouille actually put my thoughts into words, these are his impressions and agree 100%.
"I felt like you at first 'AK120 vs my ak100 modded (which I told him I the AK100 was better), but now after 2 or 3 days and using eq pro, I think it sounds great. The ak120 sound has much more note weight and depth and not only in the bass...the mids and even highs are weightier, more palpable. It feels like a higher class player than the ak100. The thing is the ak100 being thinner, it had naturally more air"
I agree with him......more note depth to me means decay, the notes last longer.
I have to say though, that the Mezzo Modded AK100 with the Listrid UI is very, very good. I had to really listen hard to hear the difference. And the owner of Mezzo, Phanom is a pleasure to deal with. A genuine nice guy and who loves audio just like us.