Although I pass through Charles nearly every day, most of the work isn't visible from the train. Today, I happened to walk past the outside for the first time in a while...and wow. It's looking really amazing.
The new portion is almost complete, at least on the outside.
The juxtoposition of old and new is typical Boston.
According to the MBTA, they are retaining and restoring much
of the existing platform structure, which is nice to see.