The best speed depends on what we weigh at that moment.
Ideally we would like to hold clean. The FMC will calculate a best holding speed for us. If it is below the max speed for the hold or the state limit then there is no problem. If it is above then we can request to hold at our best speed or use flaps to slow down if they will not or can't allow us to hold at a faster speed. For instance, there may be terrain or another barrier that requires that speed to keep us inside a specific turn radius. Sometimes the best hold speed is faster than the state limit but our min clean speed is not. In that case we would just hold at the limit or that min clean speed.
In the missed approach case it will probably be just what Al Bundy said above.