Im a big fan. used them with a naim nap 140 which I think maybe the perfect match (id even hazzard a guess at being designed with one). bass and 'size' to sound is mighty impressive (like small floorstander). mid & HF detail extremely impressive too. generally not as dull/snoozy as 11's either, have just a bit more snap to them. Imo a better spkr than 11, no doubts.
imaging excellent too, but not quite the x-factor imaging the 11's have. Only neg point: there is a lack/ bit of mid recess (a bit like royd minstrels say).. but plus points mean you don't worry really. the spkr that stayed longest in my system/ joy to have tbh. now got doublets for a better mid area, but, overall the es12 probably a better speaker.