I lean towards the upper end of the grades being offered here. The obverse doesn't appear to support that idea, but wear on the reverse is just beginning to start on the upper edges of the wings and the heck, two primary places to consider
Morgan dollar wear. So, in my mind this is a typically-execrable 1921-S strike with relatively less wear than a better strike would indicate.
EF40, but only a tiny bit of obverse improvement would put me firmly in the EF45 camp.