Mine is currently not naked, but if I use the 3500 mAh battery, I have no choice anyway.
I'm not really concerned about scratching or scraping the device. But I am completely protective when it comes to the screen. Especially since its a touch screen. I think its OCD.
I put a screen protector on my phone when I first got it, and for the most part, there were no scratches on the cover, up until when the cover decided to fall off. It also papercut my finger somehow. But anyway, the trackball stopped working, so I thought, I might as well go naked without the screen cover until I get my replacement. 4 days later, the screen is completely scratched up. I have no idea how, but it was completely messed up, to the point you could actually feel it when you moved your finger across the screen.
From that point on, I don't trust myself without a screen protector. When I got my replacement, I put a new one on immediately. I was pretty proud of myself this time, since it has no bubbles and the edges are all completely on.