I'll be curious how much lighter (if at all) this will be by the time you add the weight of the adapter, caliper, bracket, etc. typically, Devin's hubs are not as light as stock as he refuses to hollow them out for safety concerns. So you're replacing the "hub" with a larger, thicker piece plus the brake components.
May be a net loss of weight gain (if that makes sense?). But surely the braking performance will be much better: dual piston, modern rotor, hydraulic MC.