For me it's very satisfied when compared to past games. It's the favorite of all the games to me and has been for a very long time once the nostalgia wore off for the first two games.
The game works well and very smoothly for me. Bug wise I really don't see much difference all games have bugs there is nothing currently happening that I can't work around easily.
I love the way they are doing packs vs in the past. To me the general ideas of the packs are more cohesive and make sense. Then the idea is broadened with art work, animations and game play all making the focus of the pack very solid to tell a story with. Like in the past I couldn't make the kind of complete character I can now once the pack drops that has all the stuff I need to do it. I understand it's a wait but I'd rather each idea or part be fleshed out than sigh when the pack drops and know it's done and over and I won't be getting more later.
I know we will continue to get more content for some time so I won't say that certain content will make me more satisfied because I feel it's coming. I guess what would though will be continuing patches. Making the gallery easier to use or handle as it gets glutted with player creations. Letting us know that when this game ends we will still have support and some ironing out of lingering problems for awhile.
I would also be one very happy simmer if they introduced a fear emotion or at least more for modders to work with if it's against some principle they still carry for the game. It would also be nice to have some sort of attraction system if done well and some revamping of emotions to make "fine" be more of the norm even with nice furniture/decor. I would exclude turning on auras for that by the way. I think some players would like their sims to always be happy and wouldn't want to work hard every day to do that and it would be a blow to those that enjoy this aspect of the game to change it without having ways to maintain how they like to play. Maybe certain traits could come and play a role in that? It's over my head, I'm not a game developer. I'll just be happy to see these things in my game. I've avoided modding them in and I do know the mods are out there. I guess I will fall back on that one day when the game is done if it hasn't been added in.