Gauge coupling unification in the Minimal Supersymmetric Standard Model (MSSM) strongly suggests the existence of a Grand Unified Theory (GUT), which could be probed by the observation of proton decay. Proton lifetime in the p → (e|µ) + π 0 dimension six mode is proportional in the fourth power to the GUT mass scale, and inversely proportional in the fourth power to the GUT coupling. Flipped S U(5) with strict MSSM field content is known to survive existing null detection limits for proton decay approaching 10 34 years, and indeed, the lifetime predicted by prior studies can be so long that successful detection is not currently plausible. We provide an updated dictionary of solutions for the relevant flipped unification parameters with generic β-function coefficients, significantly upgrading the level of detail with which second order effects are treated, and correcting subtle published errors.Recently studied classes of F -theory derived GUT models postulate additional vector-like multiplets at the TeV scale which modify the renormalization group to yield a substantial increase in the S U(3) C × S U(2) L unified coupling. In conjunction with the naturally depressed F -lipped S U(5) partial unification mass M 32 , the F -resh analysis undertaken predicts comparatively F -ast proton decay which only narrowly evades existing detection limits, and likely falls within the observable range of proposed next generation detectors such as DUSEL and HyperKamiokande. The TeV-scale vector multiplets are themselves suitable for cross correlation by the Large Hadron Collider. Their presence moreover magnifies the gap between the dual mass scales of Flipped S U(5), allowing for an elongated second stage renormalization, pushing the F -inal grand unification to the doorstep of the reduced Planck mass.