Well, it is a science ship, and there's not a lot of things this ship should need to run away from in sublight, so I don't think having the emergency acceleration matters nearly as much here compared to the supra-light performance offered by the Big Damn Deflector Dish. Internal space is useful, of course, but being able to respond in a timely fashion to anomalies via the warp and carry out sustained operations through efficient warp engines gives better fundamentals we can't compensate for with internal space.
[X] Ovoid Secondary Hull