Maybe I have a false perception of most ADV riders being super-slab kinda adventurers. The only fathomable reason for wanting a 390 adventure bike would be some heavy off-road duty. Again just my opinion.
I can definitely see the use for this bike, but it would all depend on how comfortable it is.
Right now I have two bikes. Many times I have taken the V-strom where I probably shouldn't have, but anything less than a logging road can scare me. Getting into a muddy rut with a heavy, and top heavy at that, bike is not fun. In fact, any place that has a high risk of dropping the bike -- like a water crossing where I can't see the potential large stones; hill climbs with loose stones, etc, are all scary on the Vstrom because if I start to go down I won't be able to rescue it considering the weight.
I also have a DRZ but I am not exactly a dirt rider. I do single track very occasionally, but mostly I use the DRZ on unopened road allowances, fire roads, and muddy or sandy two-track. Obviously the DRZ handles all of that with ease, but it is not at all comfortable on the pavement. No wind protection, high revs at highway speeds, uncomfortable seat, no good way to carry luggage, etc... I'm not worried about dropping the DRZ though... if I start to go down with it, usually I can save it.
A KTM 390 Adventure could possibly fit right in the middle and replace both my bikes if it is light enough and comfortable enough. Put aggressive enough tires on it and I could do all that I do now with just one bike.
Saying that... if it has a high price tag, requires premium fuel, needs you to take luggage off to fuel up, melts reflectors by having them placed behind the exhaust, has a short fuel range, has a weak sub-frame that can't support luggage, or trouble getting insurance -- any of that -- I'm out.
