Forend design is indeed important, if we're concerned about the hands in line deal. A shallow frame gun can have a fat beavertail, which adds depth (and width) to the barrels. In contrast, looking at a deep-framed gun like the Merkel, they usually have a lot less forend wood. Then there's always the stock design, which raises the rear hand a bit if it's straight, in comparison to a gun with a PG.
As jones suggested, what works for a given individual may be a gun with a deep frame or a shallow frame. I'm not much of an OU fan, but I had a Cynergy Lightning Feather 28ga for field test, and shot that gun extremely well. Might have bought it, but I'm a fan of more classic designs.
