Really every album post-ADTOE kinda lacks character. There are exceptions. But there aren’t many.
I'm really curious to find out what you mean with this, 'lacks character'. I think they switched gears since Mangini came in and differ the style a little, but then again, didn't they also do this back in the days, with Falling into Infinity or Octavarium for example? Every single album earns its place in the wide spectrum Dream Theater expands and they're all different from one another. So I can't quite follow wht you mean.
Every album up through ADTOE each kinda has a distinct sound. The style, the songwriting, the approach. I would say SC and BC&SL are probably less distinct from one another.
Anyways, so every album since the self-titled pretty much sounds like they all could have been written in the same session. Sure there’s some variation with each album, but not that much. Even though The Astonishing on the surface seems like it’s way out of left field, it isn’t really. It’s basically the same sound if you look at more standalone tracks, i.e. The Gift of Music, A Life Left Behind, Moment of Betrayal and Our New World. Like I said, they sound like they could have been written at the same time as The Bigger Picture, Behind the Veil or Along For the Ride. That’s just how it sounds to my ears, it may not sound like that to you and that’s cool.
To me they sort of found one streamlined kind of sound and they’ve stuck to it. They’re staying in their lane. And that’s fine. It makes for enjoyable albums, but nothing that blows me away. I don’t get the same feeling listening to a new album for the first time as I did the first time I heard Learning to Live, Voices, Trial of Tears, Home, Blind Faith or Octavarium.
And one more thing, since I’m going long. I like Mangini but his drumming is just kind of sterile. His dynamics don’t really differ much from heavy songs to lighter songs. He just goes from busy to less busy. I am looking forward to hearing his solo album though. Seems really interesting.