Love these towers. IMO, far better than the generic East Asian thing proposed for the Tribune site. The cascade of setbacks and terraces mark it as a distinctively American skyscraper.
Admittedly, it does feel a little more
New York than Chicago. Our classic skyscrapers were mostly Sullivanian boxes, with a soaring vertical shaft and proud cornice. Other classic Chicago buildings had a tall boxy base with a skinny tower rising above. We didn't really have the same wedding-cake buildings that New York architects produced to comply with their 1916 zoning code. On the other hand, our classic skyscrapers were all commercial. Residential skyscrapers are a relatively new thing, there is no design language for them that is uniquely Chicago so I don't mind borrowing from another great American city, especially if it resolves the balcony problem that so many residential towers struggle with.
As for the planning concerns - I'm not too disappointed that they're planning to dead-end North Water Street. The Riverwalk and the paths along Ogden Slip are, or should be, the primary pedestrian corridors and the locus of any retail/dining in this area. North Water Street is mostly about vehicular access and loading docks. By blocking off the street in this way, it caps the vista down the street and buffers noise from LSD in a way that should make neighbors happy. With that being said, I'm sure the Fire Dept will insist on some kind of vehicular access to DuSable Park in case of emergency, either they will demand that the street be restored or the Riverwalk be designed as a fire lane.
I'm also curious to see what happens to the ramps off Lower LSD that Kelleher paid for. Will they just go directly into 400LSD's parking garage with no public purpose? (Those could also provide emergency access to the park for ambulance/fire apparatus.)