RTKL's design is ok, but really doesn't inspire me with awe... and I think looks kind of clunky and ill-proportioned from the postcard viewpoint.
I am biased, but I'll take this as the winner:
None of the other designs really start to push the skyscraper in any sort of new direction. The structural expression and continuity, subtleness of the shape of the building, and (even though not easily seen here) the way the large retail base building is integrated with the site/subway/tower all make it stand out for me. This tower is like an engineer's wet dream. I mean, come on... its a Michell's truss applied to a skyscraper!!
I don't know what is taking so long to pick a winner for this competition.