Lets see, $42.00, void warranty/Applecare, battery drain, I'll pass. I've gat a case to protect mine anyway. It'll look new when I sell it and get an iPhone 5.
Apple could never tell you took off the back unless you stripped the screws. The light turns off when the screen turns off (what i've read)...so no battery drain.
I can scratch the hell out of mine, get it dented, replaced by Apple right before the next iPhone comes out and my phone will look just as good as yours Plus I can sell it as a LIKE NEW phone since its *technically* a new phone with new parts according to Apple.