I've read The Android's Dream and Old Man's War and enjoyed both. The Ghost Brigades is the sequel to the latter of those. I like the writing; the plot moves right along, and the characters are interesting. Author John Scalzi has written a third in that series and has a fourth book set in that universe. There is a short bio of the author here.
from the back of the book:
The Ghost Brigades are the Special Forces of the Colonial Defense Forces, elite troops created from the DNA of the dead and turned into the perfect soldiers for the CDF's toughest operations. They're young, they're fast and strong, and they're totally without normal human qualms.
The universe is a dangerous place for humanity — and it's about to become far more dangerous. Three races that humans have clashed with before have allied to halt our expansion into space. Their linchpin: the turncoat military scientist Charles Boutin, who knows the CDF's biggest military secrets. To prevail, the CDF must find out why Boutin did what he did.
Jared Dirac is the only human who can provide answers -a superhuman hybrid, created from Boutin's DNA- Jared's brain should be able to access Boutin's electronic memories. But when the memory transplant appears to fail, Jared is given to the Ghost Brigades.
At first, Jared is a perfect soldier. Then, as Boutin's memories slowly surface, Jared begins to intuit the reason's for Boutin's betrayal... and the fact that some of humanity's enemies have worse things in mind than our mere defeat.
SF Signal's review gave it 5/5 stars and says it's "Fun, page-turning, well-written science fiction." Strange Horizons says, "Scalzi's prose harkens back to the Golden Age of science fiction while still remaining fresh and vibrant." SFReviews.net praises the book, opening with this: "Though labeled a sequel to Old Man's War, The Ghost Brigades is very much a stand-alone adventure. While it expands upon ideas introduced in the earlier novel, John Scalzi doesn't require you to have read it to become fully absorbed in this one. I have a soft spot for writers who are this thoughtful" and closes by calling Scalzi "one of SF's most rewarding purveyors of thrilling, gut-wrenching, and thoughtful space opera."