Going back to the discussion of the gap/cutouts and the connecting bridges, while I would like to see a couple more connections in total, I think there is a very reasonable explanation on why having only a few bridges isn't as much of a transport problem as some people might be thinking. In any Starfleet ship design, there aren't just hallways or open spaces everywhere, most of the internal space is rooms - large blocks of rooms. So if you needed to get from one "ring" to another walking or via turbolift, you can't just go straight from point A to point B, even in a contiguous saucer. You have to take available corridors. Thus you only need a few main connections between the rings. And the number of connections doesn't need to be big, especially on a 23rd century ship (compared to, say, the Ent-D).
For some reason, I hadn't originally thought of this, so I figured I would point it out for others who might have missed it as well.