I can't remember who it is, but someone I know absolutely loves his modern rifle with carving and thinks it is absolutely spectacular due to the carving.

Myself on a modern rifle, I generally do not like it. Beautiful wood grain and shape of the stock is all that is needed plus practical checkering. Of course palm cheek rests with a border, and may some inleting etc.

On some firearms of particular styles the engraving is quite apt.

As Steve says, and I thought this from looking at the photos before reading his comment, on period design muzzle loaders and similar firearms suitable carving can be quite acceptable and in keeping with the class of the firearm.

Some of the muzzle loaders in the photos look quite right.