I've read the first trilogy of novels and AVP Prey and I must say I really don't like how the Perrys wrote the aliens. Constantly bombarding us with how dumb they are, like bugs, like dogs and if I remember correctly, in Prey they added that humans were a more dangerous prey than the aliens, that was not included in the comic. The aliens have felt so degraded in those novels. Some of the writing was very interesting, but the aliens' treatment always bugged me. As much as I hate River of Pain for the huge (and some really avoidable) continuity problems, most of the characters were written very well and the aliens were treated with huge respect.
Haven't read the rest of S. D. Perry's work though, will be checking out Labyrinth soon. Also plan to read MotS and Rouge, having read the comics already.
I liked Echo a lot, hope to see the author and more women writers again soon.