I've done both. In each case, for years.
In my opinion and experience, Ball Pythons do EXCEPTIONALLY well in a good rack system.
I wouldn't keep just any species in a rack, but this one, does perfect !! For many reasons.
You will always find the people that are 100% pro racks and 100% against them. First thing, listen to people that "true and tried" both ways.
I think you CAN have both. If you like a display cage, well, keep one or two that way or get a species that likes to be out and about and then you can really go wild with a gorgeous setup and actually see a snake in it all the time. A lot of species make great use of a bigger and well lit enclosure.
I have one Ball Python in a display cage and enjoy the set up (and seeing him in it, when he decides to show himself) I also have a rack.
Yes, racks are convenient. But in the case of Ball Pythons that convenience is not to the animals detriment. They do so well in that sort of setup (if done right, of course)