I recently bought an Asp and am loving it. The jump range, the view from cockpit, the seemingly endless supply of internal compartments.. Some have complained about the old prop plane sound, I kinda love it myself. I've fitted mine for exploration, using a 6B fuel scoop, best FSD, 3A power plant (just enough power with no weapons on my build, about 12MW), D rated sensors and thrusters, a light shield generator that's basically there for protecting me should I do something stupid, some heat sink launchers and of course all the scanners required. Compared to my old Cobra, this thing melts lightyears like nobody's business. 1000 ly doesn't seem that long a trip anymore with that jump range, and don't even get me started on that 6b fuel scoop that fills me up before my surface scanner even finished scanning the star I'm scooping from. The time between jumps is amazingly short. Seriously love the ship, it's worth every penny.
The reason I'm saying all this is that even though the time difference between jumps can seem trivial, it's not once you've gone several thousand ly and intend to keep going for a lot more. You'll really appreciate the ASP in that regard.
As for that 1.6 million price difference fully kitted out.. I wonder if this is counting the stock Asp's price, or the discounted one at Alioth? Because you can get about 1.2 million off that price there (need a system permit, real easy to get), which drives that difference down to completely irrelevant.. and seriously, even a 1.6 m difference is immaterial. It's about 1-2m hours in a RES, depending how lucky you get with spawns. If combat's not your thing, run rares for a few hours. 1.6m is not exactly a huge grind in this game, and really worth getting a better ship for.
tl;dr version - if you're not already emotionally attached to a DBE, go with the Asp, you won't regret it.