it's an interesting discussion but to me at least it comes down to the collectability of the specific bike in question AND its condition. While I do agree that modern paints are far more glossy and durable than those used back in the day, there is something to be said for being able to ride and enjoy a classic bike without having to worry too much about scratching it.
Brian Baylis has done a number of "paint restorations" where he carefully masks off the original decals, massages the existing paint, touching up only where necessary, and then shoots a coat of clear over the whole thing to preserve it forever. This treatment is expensive and hence generally reserved for really rare and collectible bikes, like a 1960s Masi Special or Freddy Maerten's bike that was actual ridden in the World Championship .
However, a bike you are going to ride and enjoy reallly should have a paint job that is both beautiful AND durable, and in my view the orange Colnago discussed above is both. Many times I've leaned a bike like my Wizard against the wall of a coffee shop and people will comment on what a pretty thing it is, with polished aluminum and laser purple paintjob glistening in the sun.
Even in the realm of collectible cars, modern restorers work to a much higher standard than did the original builders. Porsche Speedsters get powdercoated sheetmetal in the engine compartment, Mercedes Gullwings get leather interiors cut from hides that would do justice to a Prada handbag. Some might comment that these are "over restored" and perhaps they are. Some of the shops restoring Corvettes took pains to reproduce the crayon marks on valve covers that the factory inspectors used back in 1965. I would argue THAT also qualifies as over-restoring.
Maybe it comes down to whether you are preserving a museum piece, or restoring a beautiful machine that you can ride and enjoy. I am definitely in the latter category.
Bainbridge Island, WA