In my opinion, Taconic is somewhat more interesting than Ekwanok, although I love playing Ekwanok. The more interesting holes at Ekwanok seem to be more towards the back of the property while the holes around the clubhouse(1,2,3,16,17,18), while they are good holes individually, you could make the case they are also fairly nondescript. Taconic, the back nine in particular, is very, very strong. I know I'm being nitpicky here because both places are in the "special" category. I just think Taconic would be more enjoyable on a daily basis but I know I'm splitting hairs because they are both terrific.
I have to admit, however, that the ambiance of Ekwanok (especially on a nice late summer day) is unparalleled. From the caddies to the understated clubhouse to the history of the place it's pretty darn good.