The frustrating thing about reading Gravity's Rainbow is that, much like Ulysses is that people say you haven't really read it, until you read it a second time. Whether that's true or not, many things become clear on a close second read. There's even a companion book you can use alongside reading it.
I say wait a decade or so before revisiting it because I think you did appreciate it. It will be there. Other than that, maybe find a new book club before these sadists suggest the Discourses on Livy or something.
which reading guide? i grabbed this one. http://www.amazon.com/Gravitys-Rainbow-Companion-Contexts-Pynchons/dp/0820310263/ref=tmm_pap_swatch_0?_encoding=UTF8&sr=&qid=