As for the cargo space issue, it will be interesting to see if the same problem exists without the Inflight Entertainment System.
Why, are they taking it out?
How much of the cargo holds does it take up? Enough for 20 Gulf traveller bags?
My point about the 319 really is that they can fly routes that the E-jet can only dream of, for example BAH-ZRH etc. or BAH to anywhere in Europe with a good load. Secondly the commonality issue, spare parts and so on.