Hey Alefattorini,
Do you still want me to compare? or are you already converted ?
I do not have a comparison for the products but I looked at both and immediately got attracted to the features of Citadel.
Let us forget about webtop is dates to 2011 and no more devs on it. I was surprised to see it listed on Nethserver.
I would agree with you on the look and the presentation of Citadel, yes it is not up to the Italian high style and design.
On the other hand I do not consider it ugly, better look would make you feel better but I would love to see it in action for its features and functionality the way it is.
Frankly I tried to install it on Nethserver and I failed, so I installed it as standalone on an Ubuntu machine to try . It is very good and I vote for it to be integrated into Nethserver.