For a great picture at the Model Y, I recommend Sandy Munro's complete teardown: https://www.youtube.com/watch?v=Br9luPS5VsE&list=PLkiDlGyJnp...

Overall the Model Y seems like a far better car from Tesla's perspective - much simpler design, cheaper to build, tons of under-the-hood improvements to make it more efficient.

From a consumer perspective, you really do get larger Model 3 - you pay a bit more, get a lot more volume, higher seating position and worse driving performance. Most of the improvements would probably only show up in comparison with similar cars ie longer range, cheaper price etc.