The Eclipse is tougher, if only because it has an inner bladder (unlike the Pioneer). If the argument is that the Pioneer is lighter, let me say that the Eclipse is light as a feather, so weight should not be an issue. The inner bladder of the Eclipse is nylon not rubber, so it is lighter than any Dive Rite wing I have seen, and it is even lighter than my Scubapro Trav-tek travel wing--and has 11# more lift. The only weighty aspect of the wing is the inflator, which has SS components--but this should be the same for the Pioneer. If you want to lighten the load for travel, I can't imagine a lighter wing setup than a #30 Eclipse with a Scubapro power inflator. If the small Pioneer is lighter, it can only be by a marginal few ounces--not worth the extra toughness offered by the Eclipse. This was my reasoning, anyway, in going with an Eclipse. Just food for thought.