I practically lived here as a student and have kept the Union in my regular rotation as a community member. There's not a lot left inside that looks anything like it did when I was a student, but the improvements are what I worked toward when I was. The most unique part of the Union is the beautiful Terrace, and that has maintained most of its charm with some great improvements like a stage with dedicated lighting and expanded seating.
The new restaurant offerings are much more modern and reflect more fresh ingredients and come closer a true restaurant experience than in past years. Costs remain low, which is a boon to students on a budget and those downtown looking for an affordable lunch.
The Rath/Stiftskellars are more or less as they were with some improved flow, but the dark beer hall vibe remains. The Play Circle is now a black box theater, and the offices on the upper floors have been renovated as well.
There's tons of free programming aimed at students and Union members, but for the most part community members are welcomed as well, space permitting.
The Union is the heart of campus - regardless of your educational path or place in the community, it's likely that you have at least one fond memory on Langdon Street. It's well worth a stop if you're visiting town, and a perfect place to build memories if you're a Madison resident.