Hi Mike,
I am using flex track for both top and bottom layers. The oval for the bottom is just for simplicity and it's more of a novelty I guess. Now for the top part, the actual track plan, I think yours looks good. I can look at curving the track and still using my three turnouts. I am not the best at track planing that is for sure. Maybe I will play around with some ideas and post them on here. What size is your layout?