When it comes to apples and oranges, business strikes and proofs, I like 'em all. My point was aimed at appearance and appreciation. While I love studying and looking at counterstamps, a.k.a. damaged coins, MS-66 proof coins are, IMHO, works of art; especially so, those early ones. With regard to the OP's coin, I do believe that the modest spread between the perceived value of the damaged 1880 nickel and a proof, MS-66 specimen would cause most collectors to opt for the proof version; this, given a choice. Beauty is one reason I'm more drawn to the proof, and marketability is the other.
@Conder101 ... By "fine" I wasn't referring to the condition of coins. Like you, I've long been captivated by the well worn early coppers. I used the word "fine" in the generic sense, as regards desirability. I am surprised that you'd opt for the damaged business strike over an MS-66 proof
Shield nickel though! I'm willing to bet that the great majority of collectors would opt for the proof.