The rest of the "champions" series all give a +1-per-level bonus to something, but the vambraces break character by having a flat weight-capacity bonus. It would fit the theme better if they gave +1 per level to something, like weight-capacity, attack, initiative, etc. Maybe even +0.1 to critical chance.
(and isn't "weight-capacity" the same as "strength" in the new system ? )