We were picking someone up at the Amtrak station on North Tryon and spent about 45 minutes at this station. (The train was 35 minutes late.)
On the positive side, there is a fairly large parking lot with free parking. However, some of the closest spaces are reserved for Amtrak employees instead of customer -- that's the U.S. government for you! The station is close to Uptown but far enough way that traffic isn't a huge problem.
This station has potential, but it's in awful condition and is badly in need of reinvestment to bring it up to a level that is not bus-station depressing. I can imagine somewhat boarding, say, the Carolinian at bustling Penn Station in New York City and getting off some 14 hours later in Charlotte. "Wow! Have I arrived after the zombie apocalypse?"