Hard-case vs Soft-case LiPos

[pug]

Hi:
I use batteries without a hard box, because I compete in electric boat races, and there weight is a very critical issue.
I say batteries WITHOUT HARD BOX, because I usually buy both types:
soft-case but that give the maximum weight stipulated for each category, or
Hard-case, and I remove the battery from the box ... more work, but high-amperage car batteries can be used

In cases where weight is very important, soft-case is best.