"First the good. You can make programs for your builds and because of this 2 trains can run at once. Also if you want you can run this with your phone. these are both awesome features.
The bad. Batteries will die on you fast. even if you have good batteries they will not last long. The batteries are also a lot of work to change. Like a lot of comments are saying, this should be a USB-C charged item, and I think that would probably increase playtime too.
I know I answered "Target" for where I got this Item. I want to clarify. I have 2 from both train sets. I got the passenger train at Target and the Cargo train at the Lego store. Both power up hubs in those sets seem to act similar, but the Cargo Train does seem to do better."