what has been bugging me ( and my users ) is media embeds. while you can just post the URL without tags in basic editor and it automatically embeds the video.. using wysiwyg editor, you must use the media tag.
and if ever you have to edit that post. it will automatically put URL tags around the url, thus breaking the embed. many of my users are not advanced users. and it leaves them frustrated and reluctant to share media.
sometimes it just dont work period. or it puts URL tags around the url on its on.