ah this is a fun topic.

Somewhere on here I read a question about the differences between and older model titleist iron and a more current model. It was mentioned that the sweet spot was placed closer to the hosel as that was where better players tended to mishit due to the in to out swing path.

I've also read on another forum that some pros will adjust the movable weight on an driver to full "Fade", this puts the sweet spot to the toe end and in effect making the driver shaft longer from the shaft butt to the sweet spot. There could be some merit to the concept.

Personally I have always preferred hitting slightly above center, since it appeared to me that it was causing higher flight and more roll. I've read that its due to the crown compressing and making the face more springy near the top. Although, depending on how I am trying to flight the ball, I might hit it lower on the face just to keep in down under the wind. So, basically what I am say is the best miss is going to depend upon what kind of flight you are looking for. Heal misses will play a fade. Toe misses will tend to draw.

Bottom line though, don't miss.

I remember reading (not sure where) that what you are saying is usually the case of how sweet spots are. Drivers are slightly up and towards the toe, while irons are slightly in towards the heel. I'm sure there are exceptions and variations, and don't believe everything you read, but that's what I've read.

The only testing I've done on this is my own, in which I tested my AP2s. I found this to be true, that the sweet spot is the heel side of center--or at least it seemed that way to me. 

Best way I found to mess around with this is grey label painters tape (not the blue kind). It works for a couple shots. You peel and re-stick it to remove your last mark and it works for a few shots. Much cheaper and easier than impact tape.