"Ugh.... if this had been taller." This phrase pops up a lot on this board, and sure some proportions would lend themselves to more aesthetically pleasing buildings, but in this case, I wishing for height for a different reason: to stand out better against the (IMO) lesser foreground buildings.
For comparison, we rightfully lament some of the infill in close proximity to the Hancock building as it blots out that masterpiece when viewed from the south. With respect to 1 Congress, there are points from the east/southeast where this building will shine, I just wish it could more effectively loom over the skyline when entering from the north.
Economics, proximity to the Greenway, angry North Enders, etc, etc... but the airspace deck in this spot would have provided 100 - 150 ft to really emerge and further stand out (750' deck here).