Re: Finally took the plunge with 18.04 last night..
I didn't find desktop too bad; it worked for the limited use case I wanted it for. Some 'interesting' decisions made by the devs but it basically works.
18.04 Server is a turd; it's one thing to completely change the way you do network configuration, quite another to have the new complicated method not work properly. I blame fiddling for the sake of it by bored inept devs for that mess.
Then I found a whole set of basic configuration options wouldn't work properly whichever of a dozen methods I tried to use, rendering the whole thing useless.
16.04 at least worked.