The tree-view in Center is far better than any overview I can find in XO.
Starting, stopping, restarting a VM is fast and natural to do in that tree view.
That makes Center useful for occasional users, that have to find a way to solve a problem, where XO is targetted at the pro user, who knows how to solve his problem before he starts.
Just to join a new server I get confused every time, and end at a place, where I have to enter its password permanently, which seems wrong.
With Windows on the workstation you have the chicken/egg problem. I run XOce in Virtualbox on my laptop. Not simple compared to Center.
XO is not cheap, and if that forces you into XOce there is confusion between the 3 versions XO, XOA and XOce, dubbed up with different ways to install XOce.
XOlite embedded in the Xcp-ng-host might change things.