Over the past 5 years I have taken 12,000+ digital pictures and this app has saved me a ton of time in organizing them (not only renaming them but sorting them into folders by date). Earlier versions were slow (though still faster than my manually doing the work it does) but this last version is MUCH faster. I don't love the interface but it works and I guess that's what counts. I know I don't even use all of its features (GREP is beyond me) but what I do use has certainly paid for itself many times over.