Agree with Chris, you can definitely manage it with smart-1 cloud instance, if thats what you are referring to. Otherwise, you still need a license, regardless if its cloud or on-prem management. In all honesty, I strongly recommend cloud instance, as if anyone makes a mistake inadvertently, you can make change on the portal from anywhere in the world to fix it.
One downside to it used to be support, as 2-3 years ago, TAC would usually have to contact R&D to fix any a bit more complicated issue with the cloud mgmt (as there is no ssh access to the customer), but now that clients do have ability to restart the instance themselves, it makes it much better, for sure.
All in all, cloud is what everyone will be going to eventually (ok, no pun intended lol)
Cheers.