yes, of course they are different, because the energy level of single-occupied excited state (S1) is different from the energy of virtual unoccupied state (LUMO), (on excitation all energy levels are change).
Aside from yes, does anyone have a sense of what magnitude in error one would receive using a ground state reduction potential vs excited state reduction potential?
In photo(electro)chemical energy diagrams, a common assumption to get the energetics of, say hole transfer from a dye to a semiconductor is to use the ground state reduction potential of the dye, and subtract the excitation energy from UV-Vis......I am just trying to get a sense of how much error this introduces