I’ve finished reading The War Against the Chtorr series, unfinished as it is.
I think they are probably best read, with long pauses between them, as they were originally published. By the end of the "last" book, I was sure tired:
Tired of worms, tired of war, tired of annoying self help gurus. Tired of... every... damn..... character...
Mr. Gerrold writes books about how to write, one of which I have read. I can't remember if he mentions this in his book about writing, but one element that is usually helpful is to have a main character that the reader likes, or can relate to.