Despite all reviews to the contrary and the reports of C5 being 'overrated', it most definitely is not.
Once you get past the rather cold and uninviting entrance, you will find yourself in the cavernous angular room. Try to get a table by the window as this offers some fine views of the city. (Once the sun goes down, the restaurant is a bit dark in the interior and makes reading the menu somewhat of a challenge).
Service by the older gentleman was warm and friendly. We were totally in love with him. The somellier was helpful as well.
The chef seems to have simplified the menu since the last time I was there and C5 is better for it. Everything was nicely done. There wasn't anything that we were disappointed with but at the same time, there wasn't anything that was massively impressive either. We had the 'From the Land' platter to share and then the black cod .. supplanted with a bit of arugula salad and a tasting of prosciutto. (yeah - the menu tips mostly to the carnivorous).
We couldn't get enough of the sour cherry sour dough bread however- much to our detriment - as it was difficult not to get too stuffed on bread to save room for the delicious meaty courses.
A good dining experience overall and most worthy of repeat visits.