[Karilynn]

Also consider the "graphics" limitations. There might be a PC who appears to be facing away from where your PC is attempting to hide, but maybe that PC is one who is often looking around their surroundings, and the graphics don't really have a way to just turn a head without turning the whole body. Plus there is the potential for someone who is perceptive to notice reflections in a window or something like that.

In general though, I do agree it shouldn't be "every single PC notices". I've played some PCs who are horrendous at noticing things (poor spot and listen) and it's made for some fun RP situations for me.

On the other hand, I know some people who've played PCs who are very perceptive (maxed out spot/listen plus feats and items), so I'd expect them to be more likely to notice such things.