Critique of each design
F1 King St. Terrace - It looks like a great space that's attractive and functional. It seems to open up access to that path connecting King and John to Metro Square, however, there should have been a diagonal path in that direction as well, creating an X with the one they currently have in their design. Their plan provides opportunities to sit and relax, as well as to socialize. It has a restaurant to draw people in and keep the space vibrant, and the sloped terrace is a nice touch. (Restaurants/cafes what Metro Square should have more of.) My criticism of it is that it seems to compete with Metro Square for prominence and use, when the latter is bigger and grander. It also removes all existing trees, which are established and growing nicely.
F2 King St. Staircase - Yes, there are stairs which serve as unique public spaces in cities around the world, but there the appeal of the stairs seems to be the diverse ways they're used in addition to providing access to a grand building. You can use them to access a grand library, just sit and relax, or do both. The idea doesn't relate to Metro Hall where you'd expect the stairs to lead to. Easier access to the connection to Metro Square from King and John through the space is potential that the space doesn't realize.
F3 Urban Ballroom - The web of lights is unique and something I'd like to see somewhere in the city, but the rest of the space seems spare and unremarkable. In fact, it's strange to see so much lighting over such a plain space. The balls don't look very comfortable to sit on and simplistic as a design detail.
F4 Entertain Me - Unlike Urban Ballroom, there's a solid design program for the space with the trees and the unique wooden structures. Yet there's something that seems uninspiring about it. There's no restaurant or kiosk, no fountain, no art, and the wooden structures seem to not provide that many opportunities for sitting, being sharply sloped in many places. Few ideas are presented as to how the space could be used and the design isn't memorable.
F5 Oracle Square - Clearly, this is the most unique and groundbreaking design. It's powerfully enough to attract people to the space on its design merits alone. It doesn't seem to compete with Metro Square like the King Street Terrace design does, rather it attracts attention to the whole block. It looks like some trees will be saved, which is good because they're a major asset that we already have. Not all have to be saved, but to remove them all would be a shortsighted waste of something great we already have. I would prefer the use of regular electricity for lighting the cylinders to solar, because it's better to have consistent lighting to make an impact no matter what the weather conditions were during the day.
Also, two clearly defined paths forming an X - one as a shortcut from John Street to King (east of John) and one from the King and John intersection to Metro Square would have made this more functional, as well as more clearly defined seating. In the end, though, this is design is fantastic and memorable, without definite functionality issues. Some slight changes to more clearly define the potential diagonal pedestrian routes through the space would render this design most satisfying.
Thus, I would rank these designs in this order from best to worst:
1. Oracle Square
2. King St. Terrace
3. Entertain Me
4. King St. Staircase
5. Urban Ballroom