This was my first purchase through the App store. So far it has worked very well. It's simple, effective, quick, and preserves all of the metadata. No complaints at all.
If you are wondering why this is needed since most have iTunes, I have found that changing the encoding settings in the iTunes preferences to be a pain. Plus, then I have to remove the new duplicate file from iTunes, and then remember to switch the settings back again before I import my next disc. This way, I just "reveal in Finder" from itunes, and drop the file on this app to convert. Done.