Well said. I guess my opinion for working doubles would be:
(1) Small to medium bore double rifle (7mm, 8mm and 9.3), go with Chapuis.
(2) Big bore go with Merkel, or if you've got the funds and want a nicer rifle, Heym.

Thats after having shot several Chapuis and Merkels. I've not shot a Heym yet, but I'm taking offers