I've been riding for 35 years. This is funny to read through this thread. People that don't like it, don't like it because "my bike is better". No one asked you to trade your bike for this one. That's not the point.
The 821 is not a "upgrade", it's a different bike. Electronics, rider aids, water cooled (and not very attractive IMO with all the exposed coolant hoses), seating position, etc.
The 797 is marketed to buyers that want a new bike, don't want to spend a ton of money, and want a simple air cooled, light, naked Ducati. Or they want a second or third bike - like me.
Ducati has nailed it by bring this back since the 796 was phased out. The 821 is not a bike to attract new riders.
How is the 797? I am one step away from buying it. Anyone has experiences with heating? I heard it overheats a lot.