I agree with Boiler. It will help you network, but majors won't care about the experience...pax airlines no longer use FE's.
Even FDX and UPS (which still assign some junior pilots to the panel) only require an FE written. Their hiring is focused on pilot skills.
ANG/reserves will not be an issue at any airline I've ever heard of, but smaller 91/135 ops may not have the manpower to cover for your absence...technically they cannot discriminate, but there is always a way around that. Personally, I will not consider corporate until I retire from the reserves for that reason.