Yes, a consideration. I haven't looked at published weights (and I would not be surprised if a bit of lying goes on!) but how they feel on the road is more important to me than outright weight. That will be where the KTM 790 excels (I think) but I don't know if I would find the engine too small and the Ducati Supersport S better.
Yes they had issue called flat tappets that should have been sorted by the factory but it did put me off a bit but i still like the look of it, but i wouldn't buy one.