I also have a vintage pair of heresies that I love, they sounded good when I found them but I rebuilt the crossovers just to see what it would do. The process is very easy, the crossover could not be easier to access and work on and in my opinion is a very worthwhile upgrade. I love horns, but they can cause headaches if not done properly... getting everything back to spec seems to have made a huge difference in this regard. What matters most is what makes you happy, but for 20 minutes of work (and a small investment) you can take them to where they were intended to go. Add a sub, and congratulations.