Is it permissible to leave the mosque after the Adhan to go to another mosque with a larger congregation, a better reciter, or to meet some brothers?

It is forbidden to leave the mosque after the call to prayer (adhan) unless there is a valid excuse. This is supported by what Muslim narrated from Abu al-Sha'tha' that Abu Hurayrah said concerning a man who left after the adhan: "As for this one, he has disobeyed Abu al-Qasim (peace be upon him)." Also, what Ahmad narrated with the addition: "The Messenger of Allah (peace be upon him) commanded us that if you are in the mosque and the call to prayer is made, none of you should leave until he prays." Among the excuses that permit leaving are: performing ablution outside the mosque, intending to return, or praying in another mosque where the congregation (jama'ah) can be joined. Sheikh Muhammad ibn Ibrahim mentioned that the prohibition applies when leaving is without a valid reason or proper purpose. However, if it is to pray in another mosque, or for an excuse, or with the intention of returning, then it is not forbidden. Sheikh Ibn Uthaymeen held the view that there is no harm in leaving to pray in another mosque if the prayer has not yet been established in the mosque one left. He also stated that there is no harm in leaving to attend a study circle or for a necessity. He concluded by saying that it is permissible to leave after the adhan to pray in another mosque if the Imam there recites better, or to meet friends, provided that the congregational prayer is still joined.