All of our Carnival ships have had a similar deck plan (2 Conquest class, Destiny and Splendor.) The biggest problem I think most have with this layout is going between the lobby and the aft dining room because the galley and mid-ship dining room do not allow passage through.
When it finally dawned on the DW and I that we could go down the deck two and pop up where we wanted to be. It felt like we have have found a "secret passage". Now we call it tunneling.
My apologies now to those who like to book cabins on deck two.