The only real problem I can think of is that if the log_archive_dest becomes full then the database will hang until space is cleared and Oracle can archive the current redo log. You just need to make sure that you have plenty of space in log_archive_dest and that you delete the archivelogs periodically (having backed them up of course). I backup my archivelogs every 3 hours using RMAN and this will delete them afterwards for me too.

Archivelog mode is definitely the only choice for a 24x7 database; just make sure that log_archive_dest doesn't fill up.

HTH

Austin