I'm going to reply here and them also post it on the XF forums to your question there.
The biggest difference is the underlying technology. The systems will be very similar in speed, support, the end result of "what you get" which is solid, reliable website hosting.
Cloud uses a distributed storage architecture, more powerful servers, and full control of your kernel through KVM virtualization as opposed to OpenVZ virtualization. What this means to you is more stability and flexibility. Stability mainly stemming from the architecture side of things - since it's a distributed storage architecture in the event of catastrophic hardware failure we don't have to physically move your data to start up your VM on a different host node. That means in a complete host node failure situation downtime is more along the lines of a few minutes instead of potentially a few hours or more. KVM gives you full control of your VMs kernel to run things such as CloudLinux, Imunify360, or anything else that needs kernel-level access.