It absolutely matters. Not as much as being still, and not as much as staying down wind, but it can make or break a hunt. And for those who say for bow it matters but not for gun, sorry, I disagree. I have been on the ground many times just sitting against a tree and had deer pass between 5-10 yards that I would not or could not shoot (e.g. not a doe day). Had I been busted, it would have ruined the chance for me to shoot other deer coming my direction also.

On the other hand, I don't believe most of the major camo patterns do that much for you (Mossy Oak, Real Tree). Because when you stand back at a distance, your outline isn't really broken up and your form can be seen. Personally, I am huge fan of ASAT camo. It completely breaks up your human form and makes you look like nothing. I've had deer look right in my direction (on the ground) many times and never give a hesitation.

BTW, cover scent is the dumbest concept known to man. The woods ALREADY smell like DIRT and a million other things. Just because you have a dirt-scented wafer on you doesn't mean you don't stop smelling like YOU. Sheesh!