It may be true that Mustangs are played out but soon enough SHO enthusiasts from the 90s would probably be all over this car plus the people who like big sedans so pretty soon SHOs be played out too.
And to my knowledge, the Mustang aftermarket is much bigger than that of the SHO, so with tasteful modding you can make a Mustang "yours."
I realize the OP said "stockish" but I'm just throwing it out there for the ones who said Mustangs are overdone.