Agreed that all of these are better than the crap JTA tried to do about 8 years ago - that wasn't even a transportation center, but a few uses that happened to be within a few blocks of each other.
KBJ is typical KBJ: Great from a distance, but unimaginative at street level. Nearly all of their downtown buildings are that way. I'd rank this third.
My first reaction was actually to like Via as the best, mainly because of cost and the vertical aspects, like stacking the buses terminals. However, outside of the skyway extension to Brooklyn (which is an interesting concept the way they did it), it's like the Skyway and Train Station were an afterthought, almost like when they were designing this they forgot about it until the 11th hour. PArt of the reason that's it's cheap is the aesthetics - a little unimaginative. Someone else mentioned an airport - I agree.
What would be great is if they could put this thing on the same lot as the Convention Center, like that private dirt parking lot directly across from the skyway station.
The Pond one takes a little bit to digest. I love the road diet on Park St (no reason this road needs to be four lanes) as well as the concepts about Jackson St. It uses the land pretty well too and considers the pedestrian/walking as a component better than the other two. It too is a little spread out, but overall nice.
I'd actually be fine with either the Via proposal or the Pond proposal, but would probably lean towards Pond because of the pedestrian aspects.
Putting them all aside, I'd REALLY prefer the ability to use the grass lot adjacent to the Prime Osborne.