Elvissey is my second-least-favorite of the Dryco Chronicles series ( we'll see where it ranks after Going, Going, Gone hits my mailbox ), but not for the reasons you might expect. Allow me to explain.
It was the first Jack Womack book I ever bought - the Gibson blurb on the back sold me - but I couldn't understand a word of it and shelved it. Somehow, a year later, I wound up with a used copy of Terraplane. I had to re-read the first chapter three times to make sense of the language, but eventually I put everything together; now it's probably my favorite. This led me to collect his other books from used bookstores, and then finally to tackle Elvissey.
Elvissey is a remarkable achievement, particularly in its funhouse-mirror distortion of the the 1954 we knew on our planet. Having said that, it's also by far the most depressing of Womack's books. Which is saying something. The odyssey of pregnant security operative Isabel and her psychologically-unraveling husband John leads them to an American South where black people no longer exist and Elvis killed his mother. Their return to 2054, and subsequent attempted conversion of Elvis into a corporate messiah, is utterly heartbreaking. This is the Womack book which I've only re-read once.
First-timers should read Womack's books in this order: Random Acts of Senseless Violence, Heathern, Ambient, Terraplane, Elvissey. You'll gradually come to understand everything about the strange future Womack paints, and recognize recurring characters.
Enjoy the ride. You won't forget it.