Once upon a time, even the awesome George R.R. Martin still had a thing or two to learn about characterization. (Read his "Song of Ice and Fire" series for some GREAT storytelling.) This was his first novel, and it shows. The main character's name - Dirk t'Larien - ouch...it fairly shouts "I've watched way too much Star Trek, and I'm trying way too hard at this!" I felt little engagement with either of the two main characters, and found myself more interested in the intricate society of the antagonists.
Still, though, you can see the seeds of Martin's later excellence in this story, and it's a neat, fairly quick read. I still couldn't care less about the main characters, but it left me wanting to learn more about all the races that built cities on Worlorn, and especially Kavalar. It was like a little tease into a vast & fascinating universe.