I sailed with Silversea back 2019, just prior to COVID. I was unable to select the correct date or itinerary from your list, but it was October and I did back to back cruises, embarked in Rome and disembarked in Barcelona.
I found both the ship and the staff to be wonderful! One of the reasons for writing this review is to give a bit of context to some of the unfavourable reviews on here, because I feel a lot of them are unfair. Particularly those written by Americans.
Silversea is an Italian cruise line. Their service and way of doing things is European and, having lived in the US myself, is probably completely unsuitable to a lot of Americans. Europeans are much more understated and their time schedule doesn't entertain "dinner at or before 6pm". Additionally, dining is about much more than food - it's about your fellow guests, the service, the beverages and the overall ambience.