I agree that, based on the Bournemouth show I attended, it was pretty much a bluesy-rock approach throughout from Dylan but it's another development, another phase in his stage career. Recently, we've had almost none of the country-based style that peppered his sets not too long ago. At some shows, apparently, he has done the occasional ballad, such as "Nettie Moore". Personally, I'd wish he would do at least a couple of these at every show.
Roughly half the 42 songs performed so far on this tour come from the 1963 - 1974 period and, when you've played 100 shows a year for the last 23 years or more, you really do have to vary things a bit to stay interested. And you try to find something new and different in songs you've sung hundreds of times.
Dylan is less concerned about technical perfection and more concerned with "feel" and the moment. There are flubs even on some of his official releases but he keeps them in, if he judges that the particular take selected matches best what he is trying to put over in the lyrics. Some might regard this as slapdash (comical, even) but it has resulted in a body of work nonpareil for a solo artist in the last 50 years. As an example, we are told, by those who have heard the session tapes for BLONDE ON BLONDE, that he recorded several different versions of most of the songs: some slower; some faster; some in different keys; and so on. It was described by someone as being more like the recording session of a jazz musician. He has often bemoaned the current recording techniques by which recordings are constructed, element by element, to produce the finished product. He much prefers to record "live" in the studio (or, at least, as "live" as possible). He likes that kind of sponaneity.
