Sinclair's science fiction romance novels are what started me on my romance science fiction project this past fall. They operate squarely in both genres at the same time. Games of Command is a slice of space opera, the entanglements of multiple space-faring governments, telepaths, alternate non-dimensions, human machines, and the complications which necessary secrets bring to human relationships.
Overall, it was an engrossing book, with deep dark sides to balance the froth of flirtful repartee, and frequent minor resolutions to balance the tension of both romantic uncertainty and certain doom. Furzel-speak stopped being irritating rather quickly, to my relief, and parts of the ending were either pat or elegantly concise, depending on how you look at it. But there were still plenty of secondary loose ends left to give the universe life beyond its last page.
Observation: The first few pages of Games of Command were chock-full of science fictional terms, place names, technology names, nicknames, and organizations. Immersed as I've been in Heyer novels lately, I noticed that an initial barrage of space-related terminology is awfully similar to an initial barrage of getting to know a half-dozen characters, all of which have a name, a title, and a nickname, any one of which they may be referred to by.
P.S. Games of Command comes out on February 27th. If you'd like more actual concrete details about the book and its plot, there's a more extensive review of it here.