Haven't heard the ACS T1 I'm afraid... The 8.A is a marvelous creature. Musical, yet amazingly detailed. I babbled some more about them here: http://www.head-fi.org/products/heir-audio-8-a/reviews/7121
Still using them 6-10 hours a day, still loving every second of it. If you can swing the $1K, forget my 2.5/5 value rating and make it a full on 5. They do classical concerts, they do intimate acoustic jazz clubs, they do pumping (eye-popping) dubstep and trance, they do shredding metal... They truly do everything well. I guess all 8 (16) drivers are there for a reason.
Edited by Sorensiim - 11/12/12 at 12:15am