my DBX does 55.25 LY on a full tank, making up for slower scooping, so I don't think my rate of travel is very different from my Asp.
I've done a lot of tests, and when comparitively outfitted and modded both the Asp E and the DBE can buckyball at very nearly the same rate of lys/hr. The Asp is only very slightly marginally quicker, like a dozen or so lys/hr quicker. The Asp scoops faster but the range of the DBE makes up for it over a long series of jumps. Yeah I know that 4A scoop feels like such a slog, but in reality it's much, much less of a detriment than it feels like it is.
I love the new DBE, and it's replaced my trusty Asp E as my exploration ship of choice.