I've got the Lycosa too, and i haven't experienced anything like that picture. To me it looks it it's purposefully scratched off for some reason.. That pattern definately doesn't look like what you would expect from heavy use.
Anyway, i have had mine for half a year now, and i hasn't got a scratch. Those low-profile buttons are incredibly responsive to game on and just as incredibly comfortable to type on. The backlight is a little insufficient if you're sitting in an overly lit room and doesn't know the placement of the buttons by heart. But to me it is not a problem at all. Not having tried the arctosa, i can just say that the rubber buttons are pretty durable and really comfortable.
I'd say definately go for it.