My daughter received this train set for Christmas. We hoped it would help keep Daddy's lego train safer. It absolutely keeps her interest (she's just turned 3) and even our infant (8 months) is entranced by watching the train.
Benefits-
The train is EASY to use. The simple push button stop and start is a cinch for her. If she stands in front of the train and it hits her foot it stops and turns off as well. If you pick it up, the wheels stop too- so we've not had any hair tangling issues (hooray!)
The duplo bricks are easy to assemble -- even for her, her buildings may not look like the pictures, but she has fun- so that is what matters.
Mixed Feelings--
The tracks are easy to put together piece by piece-- but they also come apart really easily as well. A big issue on the carpet, but less of one on wood floors. I think if you have a lego table, you can fix them down on there which would solve the issue entirely.
The track set-up(s) you can assemble with the pieces in the box is great- but my kids destroyed the box and just start attaching pieces somewhat haphazardly-- it still works, but doesn't make a loop. On that note, the train will happily run right off the end of a track piece and KEEP GOING until it hits something or 2 minutes pass. This leads to a lot of giggling at my house- but may not be your idea of fun.
Negatives--
The train has some built in safety mechanisms- it stops when you pick it up and shuts off after 2 minutes of running until you re-press the button. HOWEVER! My 3 year old did figure out how to hurt herself with it. She likes to run the train across the floor, the table, etc and decided to run it on her arm. The train wheels started turning and pulled in a piece of her skin- she was left with a small bruise from the pinch. (Dumb me in trying to figure out how the train "bit" her, did the same thing to myself too- it HURTS!)
Train time is now more supervised so we don't have that happen again- but you may want to be aware and watch for similar behaviors in your little ones.