Several users noted a marked slowdown in the bookmarking function after upgrading from 47 to 48 - https://support.mozilla.org/en-US/questions/1139318 . This bug does not affect all users since it is due to a bad interaction with the bookmark sync function; an easy work-around is therefore to switch off bookmark syncing, restoring bookmarking speed. Compared to the lag of 2-5 seconds in v48, the situation has improved but not disappeared in v49. Here the lag is notable compared to v47 but shorter at around 1-2 seconds. Switching off sync to work around this bug is not a great solution since it compromises data security/backup. Is this a bug that mozilla volunteers are considering for extermination?