Do you want a 911 competitor or a supercar? That's pretty much what you're asking.
I've spent some time in both, and the 720 (and 750) feels significantly different than the 570. They offer more "wow factor", for lack of a better term. The exterior and interior of the 720 have more detail and thought put into them. It presents as a product that more thought was put into the design, rather than the 570, which other than the doors, feels like most other cars.
For either one, you'll want to figure out where the closest dealer is and assume you'll be bringing the car to them frequently. Your other option for service is to check this guy's schedule and get on it: https://www.mcmedics.com/
I just spent yesterday at COTA in a 750S, and it's an impressive car. The August heat only allowed for one hot lap at a time, and the 750S next to us puked out coolant after it's first session, so you can't expect the reliability of a Porsche. However, if you're goal is to own something you don't see every day, that works great on regular roads, and has an insane performance envelope, it's an option to consider.