I have found it pretty easy, especially when you ditch the MDRs (let your server know in advance) and head up to Cabana's for a quick breakfast. Unless it is no longer open on disembarkation day? It has been in the past. Sometimes, one in our party will go get finger foods (muffins, some fruit, etc) and bring it to the room. The elevators can be an issue, but just plan in some extra time, eventually you will get one. We have done it with 2 rolling suitcases per adult and been just fine. Also, while the MDRs are not set up for big luggage, they will help you if needed, either by leaving it at front of restaurant or otherwise. I do not think you would be going to the MDRs anyhow with self walk out because you want to get out sooner anyhow.
Sorry for the ramble, it is fine, we find it quicker, you can get off ahead of the crowd and be on your way, of course, this is only true when the ship is on time.