It comes down to preference. The LED uses a battery that must be replaced every so often. The LED model will also allow for adjustable brightness and the ability to have an illuminated reticle in low light conditions. The Led model can also be paired with a night vision device. The Fiber Optic model collects light in order to illuminate the reticle and does not require a battery. However, since it relies solely on the fiber optic, a lack of light means it cannot illuminate the reticle.