Migrated to this extension from Speed Dial 2 after I discovered that SP2 has a serious privacy problems. Really happy that YASP saves bookmarks in browser and uses local disk for tabs thumbnails - no migration and privacy problems due to this. And yeah, that all is absolutely free!
I really miss only one feature from SP2 - popup list of last visited sites. IMO this is a very useful thing. Also I would like to have an option to remove addon's entry from right-click menu. Options of customizing fonts and changing size of thumbnails would be nice too, but I can live without this.