Cibo or Mark's hotel restaurant...
... for christmas eve dinner. Which one should we go to?
They are completely different, so it depends on the kind of atmosphere you are seeking. Cibo is a fairly large, attractive neighborhood restaurant while Mark's is small with elegant decor. Service at Cibo is fine but does not match the very polished service at Mark's. As regards the food, we haven't been to Cibo recently, but all reports are that the food's quality remains solid. The one dinner we had at Mark's was superb, but there has been a change of chefs since then, and I have not seen any current reports.
The Mark is lovely and they have a great (but small) bar to repair to after dinner. But I have to agree with RGR that they are very different and you will have to decide which best suits your idea of holiday.