Personally, I never ever use it (unless I'm super desperate, like I forgot my eraser during an exam or something. But that's never happened) because:
1. The whole pen looks ugly/dirty after just one use
2. Once you use it too much, you can't pull it out! So it's hard to stick multiple leads in.
I'm very hardcore about my pencil erasers..I remember I got a new, really nice mechanical pencil..and the eraser was never used, but during a chem lab, I left it on my desk and came back to find it used by someone. I was so pissed off.
So how about you? Do you use that eraser on your mechanical pencil?
Yes, this is very random!

























