I have an older wood EDB405 that weighs 9.5 pounds and a slightly newer one that weighs 8.5. The few Luthite EDCs I've picked up seemed to be on the heavy side, but I don't know the exact weight since they weren't mine. My 3 Luthite EDA905s weigh around 8 pounds, but the bodies are small. As another poster mentioned, they're terrific basses with a hi-fi sound.
My only qualm with the Luthite-body Ergodynes is the extra weight. By size/volume, the body on my EDB605 is smaller than any of my Fender Jazz basses, but due to the synthetic Luthite material, the EDB605 is definitely the heaviest bass I own. Not really a problem for me, but Id probably think twice before choosing it as my sole instrument for a long gig. My guess is that the newer Ergodynes got a bit lighter when they switched the bodies over to ash, basswood and maple.
Other than that, my Ergodyne experience has been totally positive.