The newly-renamed "Dark Avengers" #175 sees the creative team of Jeff Parker and Declan Shalvey introduce a new team of Thunderbolts -- although as you can probably guess from the book's new name, it's a team which contains very little in the way of faces familiar to readers of this book.
Although this isn't a complete relaunch -- Luke Cage remains in charge with Songbird and MACH-V as his deputies -- it does appear to be a genuine attempt to replace the current Thunderbolts with members of the most recent Dark Avengers team, if only to justify the name change to something a bit more saleable. How long this is intended to stick is up for debate, but unlike the last time "Thunderbolts" got a soft relaunch, the new era has at least kept the book's story and premise intact, if not its name.
Considered on those terms, there's nothing in here that couldn't have been called "Thunderbolts" had the book not been in need of a little sales attention. Parker approaches the story from Luke Cage's perspective as he struggles to come to terms with his leadership of the program, having repeatedly failed them due to his other commitments. This dovetails with both the recruitment of the new team and his eventual decision about his role alongside them.
Clearly, then, this isn't a story that's been tossed out as a deck-clearing exercise, and the presence of the Dark Avengers seems to be part of a larger storyline rather than an attempt to supplant the present one. That alone can give long-time Thunderbolts fans a reason to stick around. Parker's character introductions are capable and the characters instantly engaging, but most commendable is his attempt to give the book a structure apart from the typical "team round-up" issue that we've all read a hundred times before. It might say "Dark Avengers" on the cover, but this is an issue about Luke Cage, not the Dark Avengers.
Shalvey and Martin's work retains the book's usual tone -- gritty but not grim, action-packed but not messy. In particular, Shalvey's work on the incoming Dark Avengers characters quickly establishes the character of each. Ai Apec in particular is a very different Spider-Man than we're used to, not just in appearance but in posture and stance.
Aside from the name change, it's business as usual: strong characterization, great art and the same villains-as-heroes premise. Whether this "new era" grabs you ultimately depends on how interested you are in the incoming team and how willing you are to wait around for the old one. Other than that, the outlook looks promising.