You can set preferred bitrates and filter the listings (thousands built-in or add your own) based on bitrates or your own ratings. Search by keywords in titles and descriptions and narrow down the very general genre categories to your particular tastes. The built in player works with stations or tracks you've recorded, and has a minimized "Remote Control" view, easily triggered with a Command-2 shortcut. Optional Growl-like notifications keep you up-to-date on what's playing and what's recording.
You can organize your favorite stations and tracks with folders and playlists. When it comes to tracks, I'd much rather build an iTunes playlist, which is a simple matter of highlighting the tracks you want to keep and hitting the "Send to iTunes" button on the track page. You can set a preference to have tracks removed from the Radio Gaga folder and track listings when they've been added to iTunes. I'm unsure, as usual, about the legality of recording 'net radio in this fashion, and what implications it has for the stations themselves. I guess we'll see.
The program is polished and usable right now, but I'd love to see a few things improve: better keyboard navigation and configurable hotkeys, on-the-fly normalization, an option to save only full tracks, and a track/artist display in the mini-view when listening to live radio. Despite my nit-picking, the app is really impressive, and thanks to a special introductory rate at the MacUpdate Promo site, good through July 19th, I picked it up for $19.99US. It will be $39.99 after that, but you've got a few days to take advantage of the intro rate. A free trial is available, check it out.