I'm in my 40s and ride in what you'd probably describe as a "spirited" style. Consequently, my opinions are molded by my riding style. Most of the folks I ride with ride Brit, Japanese or Italian, none ride H-D. The reason is b/c it's a cruiser and not suited for any real level of aggressive riding.
H-D are street bikes, period, yes, even the nightrod. H-D is on the other side of the fence as far as the 848 is concerned. The nightrod is not meant to be a performance machine and was certainly not built on racing cred like the Duc. It can be modded to go decently fast. . . in a straight line, but that's about it.
If you're going long distance, there are other bikes that would be a much better fit.
I think the 848 is a more genuine bike as it doesn't pretend to be anything it isn't. Nearly all Ducs, with the exception of the Diavel, are literally built upon an actual racing heritage. Names like Polen, Fogarty, Corser, Bayliss, Hodgson, Toseland, Hayden and now Rossi have ridden and won on Duc's very very similar to the 848. The chassis, forks, brakes. . . every piece is connected to it's racing past. Even the Ducati Monster has a similar frame and components to the early WSB champs.
I'm tryin' real hard to think of champions who've ridden for H-D within the last decade or two. Once upon a time, H-D did make a killer race bike, the XR750. This bike is the flat track legend that Chris Carter dominated the Ford Flattrack Series (and the only H-D I'd ever own). Not to be confused with the bloated XR1200, that sports faux gas tank. The only actual race bike H-D had was the Buell 1125R Danny Eslick won Dayton in 09 on it. Of course, H-D got rid of Buell, so. . .
As far as image goes, if you're buying a H-D to be "cool", you're about 5 years late. That time has come and gone thankfully. If you're buying a H-D for value, you're in luck as you cannot swing a dead cat on CL without hitting another H-D up for sale, they're everywhere and relatively cheap.
I know you mentioned "new" motorcycle, but I'd definitely recommend you look at the used H-D market seriously, as you will find many many used H-D on the market with very low miles. Ducati's less so but there are deals out there if you look. Expect huge depreciation on any NEW bike (H-D or Ducati).
With regards to riding either a Duc or a H-D I'll say this. . . I've never passed a Ducati rider that didn't give me "the wave" back. . . as far H-D riders go, I'll say. . .I've never passed a Ducati rider that didn't give me "the wave" back. I think many H-D riders have a bit of a Walter Mitty complex. . . Duc riders do too, but they all want to be Rossi, which is forgivable.
Get the Duc.