I believe the Captain should take control once the emergency has been delt with and the aircraft is returning for landing.
If the captain takes control too early his/her decision making will be slower and less thought will be given to his/hers actions. Manually flying the aircraft requires the concentration that could be better spent on making good decisions!
Let the F/O fly (as long as he is handling it well) and the Captain carry out check-lists and radio work. Because the Captain has the final say, it would be easier if he/she gave intentions directly to the controller not through a worked up F/O.
chink... chink!!!... There's my two cents worth!!!!