Do you guys know if there's any difference between the two other than the Fill? It seems like if not we're paying $56 extra to have the bag filled by wiebad.
You have to buy the fill bags for the modular pump pillow seperately. I think it's actually a few bucks more fore the modular pump pillow and the appropriate amount of fill bags.
I used some to replace the plastic BBs in a TAB rear bag. It feels identical to what is inside of my pump pillow and reduced the weight to almost nothing.