Hi Jang,just watched the video with your new Lego City... totally awesome, but where's the palace cinema? :)
In regards to the Lego train noise as requested a response I don't mind the noise. In your case your voice and well articulated speech and soothing voice cancels out the clatter.Aloha Clint
In my opinion the trains are too loud. It's difficult to concentrateon your narration. Have you thought about getting a specialised microphone? I think there are some microphones which are able to dampen/filter out such background noises.
The trains during a portion of the video wouldn't be that bad. I really had trouble focusing on what you were saying when the trains were going. My son would love for you to mix new and old Nexo Knights.