Yes I think so. It is a great upgrade. The utility that flight brings you in a 6 inch aura cannot be overstated, particularly for keeping your models in cover then jumping out as, lets face it, most nightmares are squishy. Also Wk 5 vs Wk 4 is a massive improvement, meaning she can keep up with constructs in the crew to give them +1wk and also meaning she can get into the action (if using her as a beatstick model).
Most importantly, however, it frees up an upgrade slot on the Dreamer and means the aura is always in play rather than disappearing when Chompy comes out.
Plus, who doesn't want a flying chompy?