Yeah, of course that will be instant.
I am pretty well satisfied with the design now. Either the client or the server can create an entity and upload it to the network. If you have a fast-paced FPS or racing game, just let each client control their own player entity. If you have a physics-intensive game and are comfortable playing only on low-ping servers, let the server control everything. You might be able to create a controller on both the server and client ends, and do your own comparison, but I am not too worried about it. The point is that once you sync an entity, you can move it around, let physics move it, free it, and it will automatically be updated on all the clients, which is fantastic.