Just finished The Quiet War by Paul McAuley, my first book from him. I enjoyed it but wasn't bowled over. I thought it was well researched as hard SF - his descriptions of the colonies on the moons of Juptier and Saturn were thoroughly thought out. Maybe a little too thoroughly though, I found some of the detail a too much. Also there were a few deus ex machina moments too that irritated me. Finally the ending was very week and inconclusive. I know there is a sequel but it wasn't really billed as a series.
However it was good enough that I shall probably try more of him, in particular I liked his well thought out and scientifically feasible future.