Re: Mick Thomson Siggie
I went from a strat with dots, to a viper with flags, to an S2170 with only a 12th fret inlay. It won't bug you much, and if it does you still have side markers. On board inlays are generally just for decoration.
THe best way to check it out though ,is go and play a few guitars with no inlays or only 12th fret inlays. YOu'll see if you find it wierd or not and most guitar shops have at least a couple. Personally, I think if you're a reasonably confident player its jsut an adjustment rather than a hindrance.