From a practicality point of view, if you measure the width of your garden variety SxS 12bore with a splinter forend, somewhere in the middle of the forend, you get a measurement of around 5.3cm. If you take your average 470 with a beaver tail forend and measure at approximately the same point, you end up with a figure in the vicinity of 5.5cm.

Generally speaking, if the garden variety 12bore with a splinter forend is comfortable and easy to point, I would say that your 470 with a beaver tail would be just as comfortable, seeing the grip radius is just about the same. Fom an aesthetic point of view, that comes down to personal preference and we can argue that point till we are blue in the face.