Isn't that amazing! The only question I'd have is how you'd get a replacement 15 years later or 5. I'm sure you need to have a proof of purchase so the chance of finding the receipt is pretty slim. The only think I can think of is scanning them and filing in a warranty file. I know I bought a garden hose that had a lifetime warranty. I even knew where I put the receipt. However, when it failed I looked where I filed it and it was gone. I probably cleaned out the filing cabinet at some point, forgot about it and it became trash.
They had bulbs at HD today that had 26 year warranties but for the difference in cost, I went for the sale bulbs.