The AT midrange is very smooth with great detail. My previous experience with AT drivers was limited to one woofer that was sent to me a few years back for a 2-way design. While I felt it was a good driver I thought there were better options for less money. This current unit is different in that it's optimized for midrange use. It shares the same excellent motor structure but changes have been made in other places to focus on midrange performance.
As far as comparing to the Accuton dome midrange in the Estremo that's difficult because it's an apples vs. oranges comparison. The AT having a softer poly cone is probably a little more forgiving and of course not as wide in horizontal coverage due to the larger surface area.