1. Update completed quite quickly, with no issues during download or installation.
2. No impact on current configuration of watch, that is no loss of music, apps or current configuration.
3. Upgrade appears to mainly consist of Samsung Health upgrade and April 2023 Security release. However, my Spotify library display appears to be quicker and listing individual tracks in albums and playlists differently. May be just me though.
So far a pleasant experience, hopefully we will soon join the monthly security release policy.