Harmattan is the one to use. All other are just proof-of-concept (you may check 'ubiboot') if you like). Facebook IDK but I guess it is broken. Email works flawlessly. Maps is perfect after enabling developer mode and editing two config files (do not have the link at hand but http://talk.maemo.org/msearch.php) First thing to do is download ancelads n9 repo mirror from openrepos.net and tap on it in download window. This will disable old deprecated Nokia repositories and switch to a mirror. Second would be to install warehouse from openrepos - the synonym for Nokia store. More?