I just got the 3790t and New York City Explorer download.
The physical GPS function appears to be in good working order, but since I am not located in NYC, I want to try it out in the simulated mode and use the Trip Planning feature to explore the 3D modeling function as well as to learn the Transit information--routes, stops, train numbers, and amount of walking involved.
I cannot find 3D images of buildings. Pedestrian mode does not offer that option.
Setting My Location in order to plan the trips is not a straightforward process, although I think I may have found a way to do it using Coordinates. My first several attempts, it started my simulated trip from where I set my starting location in NYC, at other times from my last GPS position. Several steps were involved in these attempts.
I may have found a way to set the virtual, simulated Home by entering Coordinates. I discovered this method after my original post and have edited it for that reason, and when I have worked out the details, I will repost.
I have contacted Garmin support, which I have found to be very responsive.