Well, I was going to post this in the "Are DT getting stale" thread, but it's locked. Still, since I spent 10 minutes writing the post, I might as well post it somewhere, since I don't think it violates the rules like the OP did. Anyway, it's also on topic enough here:
Are DT Getting Stale (Without Mike Portnoy)?
Here's my perspective: I'd say the last several Dream Theater records with Mike Portnoy were pretty experimental, in the sense that through that era the band often tried to mix more modern influences (Opeth, Muse, etc.,) into their formula, which is seen at various places from SDOIT - BC&SL.
This experimentation away from the usual DT progressive metal sound was always a little risky for the band, and often divided fans. Some people love the Opeth influences on songs like "Repentance" and Muse influences on songs like "Panic Attack", while others did not. Some still really liked the more "modern metal" approach of Systematic Chaos and Black Clouds, while others felt isolated by that sound. And so on.
Anyway, after Mike Portnoy left, it felt like the band really needed to take a breather and reflect on the last few years to decide what of the work t they'd done had been successful, and what hadn't. In my opinion, A Dramatic Turn of Events was really just that - instead of veering of into new territory, it simply contained all the best, most tried-and-true elements of Dream Theater's music through their career. In my opinion, it is the consumate "Dream Theater record" and exactly the record the band needed to put out at that juncture in their career.
That said, I am a little bit disappointed with DT12. To me, it's the same thing over again. I hear lots of DT sounding like DT, and lots of DT sounding like Rush, but very little of DT taking chances and challening themselves with their music.
Maybe I'll warm up to it with more listens. For now, I do like it, but while I'd say the band are short of "going stale", I sure do hope they mix things up a bit more and get back to dicing things up a bit.