I got the first book as a freebie/promotional Kindle book, and it was decent enough to continue on with the series. It's a fast and not especially "deep" read, but the combat scenes are well plotted and paced.
If I had but one complaint, it's that the military vernacular could be tightened up quite a bit. It should be concise and straight-forward. The conversational tone of the automated computer announcements, for example, is just wrong for military sci-fi.