I've been using this plugin since before the media manager update. It does exactly what it says, without any bloat, and is invaluable for my website.
I use it to attach images to pages to create portfolio galleries, and it's now even more useful with the new media manager in WP3.5 - adding multiple images at once is a brilliant time saver.
When I ran into some problems with the upgrade, Jonathan sorted me out within minutes of me emailing him. I've never experienced that kind of support from software I pay for, let alone something he is providing for free!