After some additional thought on the former Questar, Bar X block, I came up with some ideas. I think a does a great job of breaking up that block, the new N/S street will enhance the mid block pedestrian corridor from 150 S all the way to the City and County Building. The placement of the two new office buildings will also help fill in a few gaps due to most towers being on corners.
Aqua - new two way streets
Yellow - new one way street, alley or pedestrian access.
Deep Red - new office, including the proposed Boyer on the SE corner of 200 E and 100 S
Dark Blue - highrise residential
Green - open Space
Purple - 1-3 story retail, possibly residential above
Red - Bar X