I've stayed in a lot of hotels and this one is easily in the top three. If you have the means, I highly recommend it. I got upgraded to a suite, which was absolutely enormous, with two huge rooms and at least twelve-foot ceilings. I particularly appreciated the large windows that let in a ton of natural light. The king bed was one of the most comfortable hotel beds I've ever experienced, the A/C worked well, and the room was extremely quiet, so I slept fantastically, which is my number one criteria for a positive hotel rating.
In addition, the customer service was "above and beyond" friendly and courteous at all times, room service had great selections, tasty food and arrived at the exact time specified.
The hotel lobby of this onetime train station is beyond belief, and makes an impressive first impression as well as a great location for drinks in the evening.
The location of the hotel is also fantastic, just a few blocks from the main "Lower Broadway" section of Nashville.
I was extremely impressed and would recomment the Union Station without hesitation.