Not really. The most important thing is salting ahead. Marinades really only penetrate so much, no matter how long you leave them. Most of the flavor is on the surface. And if there's no salt, they're even more pointless.
That and acidic marinades really shouldn't stay on meat for very long because the acid breaks down and "cooks" proteins leading to mushy, somewhat pasty meat.
This is why fish shouldn't be marinated with acid. You're effectively making ceviche, which is nice if you're making ceviche, not if you want to cook it.
Originally Posted by Saria
I heard the acids make the meat more tender, is this not true? Is it bad for you? When you say salting, how do you do that with chicken breast..and it makes a difference if you do it overnight vs same day?