If Holland and Holland is the number one name I associate with double rifles, then Purdey is number two. From an aesthetics profile, I prefer the more classic lines of the Purdey over the Holland.
Purdey coined the term Nitro. If a genie granted me the wish of a double rifle, it would be difficult but I would probably ask for a Purdey in .470 NE over a Holland. From what I can gather, Holland does not make doubles in .470 caliber.