Bourbon is fickle to me....I recently finished off a bottle of Antique 107 recently, and it was very good....but my palette found the much cheaper (and more available) Special Reserve more appealing. Given the SR is about $80 cheaper around here, go figure. The more bourbon I try, the more perplexed I become. I also have an $11 bottle of JTS Brown that is infinitely better (to me) than an $80 bottle of Knob Creek 12. The more ironies I find, the deeper I dive into this beverage. Keep in mind, I'm in WI, and bourbon here is very high-priced and hard to find (relative to southerners in general.). I also find EH Taylor small batch far more drinkable than EH single-barrel....maybe it's just me.
Bourbon can be made at 10000 different combinations in % of grains, thus the complex array of difference in flavors (and proof) in bourbon/whiskey.
Bourbon regulation is it must be 51% corn. The other 49% can be any combination of rye, wheat, barley, etc… so think of a bourbon.
51 corn, 20 rye, 29 wheat
70 corn, 21, rye, 9 barley
60 corn, 38 wheat, 2 rye..
…. And on and on and on and on and on… % mixes galore.
Then mix in proof from 135 down to 90 and any combination thereof…
Whiskey from just one distillery can be an amazing mix of proof and grains..
Thus your Weller example is so diverse ….
Its trial.. and error
One may love a whiskey from a producer but dislike their next offering or style…