The "Flesh-Colored Bandages" panel at WisCon this past weekend was a really fascinating conversation that touched on exactly this topic -- I'll try to get my panel notes typed up within the next few days and give you the link, but this is in my notes (not verbatim, I missed a lot) from Sandy Olson, who is a person with a disability:

"How does the cyborg feel about his own body? There's a dream of transcending your body. I don't buy that. I have chronic pain, and -- you should enjoy your body. I can't replace my body with a new one. Okay, I'll talk about Avatar... giving up my old body to get a new perfect one, I don't buy that, I don't want that dream."