I'm pretty sure I know where the photograph is of myself and my brothers next to the Choo Choo when we were children, so I couldn't imagine not taking the time to see it again - moreso for me, a little bit for the kids.
It's in a very run down area - didn't feel comfortable there during the day so I can't imagine being a guest there at night. We had to park in a paid parking ($3) structure shared by a public transportation depot (electric shuttle). There is Chattanooga ChooChoo paid security guys posted between the parking structure and the ChooChoo grounds, which is a tell-tale sign that you are in a sketchy area.
We were in and out of there in about 20 minutes. I would have stayed longer if the ice cream shop had been open, as that would have been charming, but we were there long enough to stand on the train, walk along the train, take various pictures, read some signs and get out of there.
I didn't bother with the trolley or the gift shop, and although the website leads you to believe they have a beautiful, vast garden, it's really just a few large planter boxes and a fountain. Beautiful, but you couldn't spend an hour walking through the flowers - it's 3 minutes, tops.
It was a kick to see the train, take pics near it and explain to kids the significance of the train, the song and how the station looked in its hay-day, but get in and out, don't pay for extras other than your $3 in parking.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.