Thanks for clearing thing up a bit guys, I guess the lines on the back of mine is from breadkniving or something :)
Bjørnar: It would be interesting to compare them, but I think Glen made a valuable point, I don't know about yours but mine was pretty roughed up when I got it so I've lapped it on 320 and 600 wet/dry sanding paper.
I guess we still could get an idea if there is any big difference, but from what I understand a comparability test will be hard to do.