E.T. is correct in saying that if you don't know what you are doing go with managed. When I upgraded from shared to vps, I went with managed while I was doing the learning curve, however I did spend 5 years learning linux at home. I learned on ubuntu, and it is different than learning on centos, and different than learning about a hosting environment, that is completely different.
Even as someone that knows a good amount with how linux works, I still go with managed to relieve the stress of worrying about things. For example, if you need a server audit, and have no idea how to deal with that, that will be included in your managed hosting fee, regardless of how much time is required. If you went with unmanaged and needed an audit, you could pay several hundred dollars up to a thousand or more.
Just when you think you know something with managing a server, you find out you need to learn more. Managed hosting can be a savior when you have a hardware failure, or your VPS just goes for a crap on you, or your VPS node gets overloaded.
Important considerations to make with a VPS, you are responsible for backing up all the content. Your webhost may make a weekly snapshot, but that could cost you to get that snapshot activated. Always check out the VPS provider you intend to use, ask questions, get information..