Thanks for taking the time to share your experience. It was a detailed and balanced review.
I have sailed with Crystal and would agree that their enrichment program is more comprehensive than Silversea. If you are looking for more active cruising have you considered trying some of Silversea's expedition cruises? Active during the day, but quite low key entertainment in the evening due to the smaller size of the ships.
I agree with your comment about the unimaginative cheese offerings - this was feedback I gave during my last trip.