I personally get the idea, but I dislike it. I personally find that it would be much simpler, for me, to half my party's PER roll. Thus, it makes it much harder for The Bat Ninja to notice something and not just notice it automatically. The incredibility of his PER roll counts against penalties, not casual observation. I don't believe that just because you have a high PER means that you notice EVERYTHING, but it does mean you notice a lot. It's like the old phrase "Even the greatest can't do some things". I cannot force myself to give a player everything I am planning for them just because they have a high PER modifier, a high INT modifier, a high Tactics modifier, or even a high Analyze modifier. One more thing. I'm not saying that this idea is bad, per se. I'm just saying I dislike it.