I've shot both the Merkel and the Krieghoff in .500 NE at the Vintagers events and feel that the Krieghoff fits me much, much better. The length of pull and the drop at heel are spot on. I like the Merkel actions, from which Rigby also uses for their guns, but the stocks don't fit me at all. Of course, gun fit is paramount in a big double. I really like the Heym, also. They also fit me very well. If I had to pick my favorite and I had the money with all of the guns lined up in front of me, I'd be hard pressed not to go with a Verney Carron. They look incredible and the triple locks really do something for me.