There have been great strides in modern production film capacitors, resistors, inductors. Check out brands like Jupiter, Duelund, Jantzen, Audyn, Miflex, Mundorf. Could go on and on. You can 'tune' speakers to individual preference with judicious choice of components. My present Klipschorns most definitely don't sound like any stock Klipschorn. The necessity of replacing certain crossover parts, and perhaps speaker surrounds as mentioned above, are an advantage of purchasing vintage, IMO. You've already opened up speaker, perfect chance to upgrade, no warranty issues.
Not willing to open up and mod or replace, stick to modern.
Not willing to open up and mod or replace, stick to modern.