I've been waiting for this particular review with the proverbial bated breath. Locus magazine, which is the multiple-award-winning industry review and news magazine for SF and fantasy, has reviewed Ashes of Candesce. Russell Letson knows the series, and so he's in a position to compare Ashes to Sun of Suns and the rest of the Virga books. He puts it this way:

Because schemes and puzzles have been staples of these books from the start, one expects to encounter hidden agendas, mixed motives, secret histories, confused or conflicting loyalties, concealed plans, and unmaskings. But alongside the engagingly busy cut-and-thrust of the intrigue plot runs an equally intriguing component of the book – the play of ideas and science-fictional inventions that make this more than a cunningly engineered thrill ride – and a deeper kind of fun starts when those plot secrets and revelations connect with that layer.

--And, in terms of where these books sit in the broader field of science fiction, he makes the observation that 

All this clearly places Schroeder’s work in discussion with that of Greg Egan, Kathleen Ann Goonan, Ken MacLeod, Charles Stross, and Vernor Vinge, among others.

...Which seems about right, considering my obsessions and reading habits. Mitigating this somewhat daunting list of comparisons, though, are Letson's closing comments, where he says

In a recent (as I write this) Locus Roundtable post, Karen Burnham posed the question of the appeal of SF and fantasy – ‘‘Why do you enjoy this crazy brand of literature?’’ I responded with several paragraphs of babble, but I think I could have just offered this series as my answer.

Thank you, Russell. And adieu Virga, it's been a great ride. Time to move on to something wilder, and to those ideas that have been bottling up in me since I began this series... seven years ago, now.