FWIW, the 2013 is still drinking very well and I had an older bottle late last year which can be dated in part by the label:
This bottle was from before 2004, so it was at least 15 years old. Still with some effervescence, it is showing its age with some forest floor elements, but it still has enough fruit, off-dry sweetness, and acidity to be enjoyable.
I’ve always thought of it as a fun yet engaging sparkler. I’ve fallen victim to Jon Bonne’s “American neuroses about sugar” and haven’t tried one in several years. Probably time to challenge the reluctance.