Bon Jovi has been changing there sound on every album sinds NJ. I think they attempt to sound modern every time the style and music of the whole industry (labels, MTV, charts) change. They are afraid to be completely artistic and keep their own style, because everything must sell. IMO all that changing, after These Days has affected their songwriting. They try to hard to be different, and to get new (younger) fans with every album. But in the long term they might lose the older fans for the same reason.
Their best album, IMO These Days, did sell bad compared with the other albums. And at that time it maybe wasn't to awful because Cross Road was selling millions and millions. But now there is TLFR, and that isn't really a second big selling CR, the same you can say about the box. I think the record company now wants to make some big money.

So I'm very curious if there will be a complete different sound again, or that they decided to make an album that is so good that everybody wants to buy it because it is that good and not because another "Misunderstood" is in the top 20 of the charts.