There are many reasons why I carry multiple molds of the same disc in different weights.
A 150 R Pro Boss goes a zillion miles thrown backhand and downwind for me, but its too flippy to forehand, so I carry a Starlight 167 Boss for forehand duties. The Starlight I have no way of getting up to proper speed backhand, so I need both discs.
I use a 175 Champion Valkyrie for flat and downwind shots, but its not stable enough for strong headwinds, so I have a 161 Star thats alot more stable for upwind drives. The heavier disc does go farther between these two, which I attribute to better glide.
I carry a very flippy 150 Beast for long range downwind hyzer flips, and a more stable 165 Champ for more controlled distance drives that I need to turn less, but still go far in any wind.