Total props to the Alchemist for inventing the style. I've never had Heady Topper, but wondering if your thoughts about it have changed over the years? My sense is that some folks now see it almost as a precursor to the current NEIPA's, which are getting ever more juicy.
Heady is different from what most people associate as a NEIPA nowadays, if for no other reason than its firm bitterness. My wife and I go to Stowe every winter to go snowboarding, so I don't get to drink it regularly, but I have had it multiple times. There are small differences in the beer that John admits to because he harvests and reuses the yeast. Over the years he knows how many times he can harvest it before the yeast no longer delivers what he is looking for in the beers. I've also heard him in interviews talk about how they blend multiple fermentors together at packaging to produce a repeatable product, but how he will at times play around with one of the variables in one of the fermentors. This allows him to taste how that variable changes the beer by tasting the beer straight from the fermentor, but then he can blend it back in with multiple other fermentors before packaging. If he thinks the variable provides an improvement without changing the overall beer he will implement that variable in future batches. Don't quote me on any of this, I'm regurgitating it all from memory.