Performance-wise, even with asynchronous loading, the loading of all the AddThis buttons for all the posts on the homepage can be somewhat a drag.
It would be nice if under the "Show on homepage:" in the Advanced tab, there was a sub-option called "Only on the first post:".
This would be useful not only for performance, but also for bloggers who just want it to work this way. WP Greet Box works this way.
