I did enjoy my Mini96 and sometimes I wish I still had it. There are times the dog goes with Dad away on trips.

I would highly recommend the Mini96 for the Dnano's with the proper PN tires. The cars will rocket all around that track. As I have no experience with any other kind of track, I can't say anything about the other choices.
But from my previous Mini96, it's well worth it. I feel the Mini96 is perfect for the Dnano's more so than the 1/28 scale cars. The Mini-Z's just felt too tight on that track.
From what I understand, with the right tires, the RealTracks are just right for the Dnano.
I'd like to get another track for my self one of these day's now that I have four cars to run with!