I understand your points made about a well centered note Ottawa. I cannot think of any long time collector who would disagree. However, I think what happens is that we wait for a certain note to be available for purchase, then see one available and may snap it up regardless of how imperfect it might be.
For example, I bought a Beattie Coyne *A/D a few years ago that was graded by the dealer as UNC. It would be UNC 60 now but I think I paid book (or more) even though its well centered but the upper margin had orange/reddish band marks in the centre. Some collectors chided me for purchasing such a note, while others drooled. The thing is... I' waited and hadn't seen that note for sale so I snapped it up when, perhaps I could have bought one nicer. I also have some less than perfectly centered 1935's in VF which I'm happy to have to complete my BOC collection. While I appreciate the 35's they're not truly what I specialize in collecting so they satisfy me. I doubt I'll be selling them any time soon. The 1937 issue is in the same boat (not my priority). I bought 3 less than well centered consecutive UNC 's for such a good price -- I just couldn't refuse.
I think centering is certainly critical in pre-1954 notes, but is much less important as we turn our attention towards the post-1970 issues. In the early issues where many of the older notes were cut by hand, or where finding a good jumbo border is plain hard to get --then yes, its more relevant than a note poorly centered. However, most collectors I know are more concerned about the grade of the note than just centering alone. For me eye appeal is a combination of many factors, and I just can't bear stains, pen marks, edge tears, or pinholes. As R_P puts it - nice original notes, with nice clean paper quality is more important to me.
I have always thought that there are 2 kinds of collectors: A) those who regard their collection more as an investment portfolio, and B) those who regard their collection more in terms of a prized collection of asthetically pleasing hard to get notes. Typically type A collector is the one who obsesses over the 60-66 of his UNC's while type B often has a variation of hard to find UNC 60's and mid-grades that have super eye appeal and cover certain corners in terms of completing areas the collector has been specializing in. I'm sure that type A collector will do better in selling his collection at a premium (& make a greater profit) than type B... but that's type A's intention whereas type B just collects for the love of the hobby.
I believe when you get committed to trying to obtain a certain corner of a series, or a set of notes (be it radars, DF's, asterisks, or change-overs) you can over look some imperfections (esp if you are a type B collector).
