Rocket developed many issues with missing notifications and messages for me over time. No push notifications on mobile when a desktop is connected. Overall things fail intermittently especially when multiple clients are connected for the same user. At some point it stopped respecting some settings about the per-room notifications.

My experiences both as a Slack org owner and a Rocket org owner - I'd set aside my personal dislike for Slack to use it over Rocket ten times out of 10. The admin tools for Rocket are really sub par.