GraphicConverter has two main faults, that I can see.

The first one is more transient, and is not about the app itself as it is with the upgrade process: The author releases so many incremental updates that users get into a years-long habit of automatically downloading the new version and trashing the old one, which means that on those rare occasions (2002, 2007...) that the new version requires an upgraded license, the author uses the same old upDATE dialog. Users get fooled into overwriting their old version with the new one, and are only then greeted with an unexpected "pay up" screen.

The second fault is that over the years that GC has been developed, the user interface has not grown in elegance. The Preferences dialog especially is labyrinthine and unwieldy -- searching for a way to set a specific option among the nigh-infinite possibilities strains patience. Additionally, as a previous reviewer commented, I have to agree that the interface looks like an application from the late 1990s that's been recently carbonized, instead of a mature cocoa app waiting for Leopard. The toolbar has only the most primitive Microsoft Word-ish customization interface (and its new "large icons without labels" option in the browser is somehow an odd size vertically...), the Preferences dialog has no tooltips to help me with its myriad options, and (although this is embarrassing for a user registered since 1998) I still can't quite figure out when and where the toolbox palette is or is not going to show up... XD There's something just wrong with that...

The author has made a number of interface tweaks in v6.0, but they appear to be totally random, at the author's whim (the toolbox icons are now gigantic, the tool area at the bottom of each image window is now half-again as tall as the scroll bar and noticeably reduces the real estate available for displaying an image). As far as I can tell, the author has either never read, or understood the reasoning behind, Apple's Human Interface Guidelines documentation, even 6 years after the release of OS X. The GC6 interface has changed a bit, but since the changes are in no particular direction, it hasn't really improved things much.

All that said of course, paying $20 once every 4-5 years is a no-brainer. There are times I just don't want to fire up the behemoth Photoshop (though at 94MB, GC is itself well into the same category), and GC is consistently a welcome tool in my toolbox. The two faults above only add up to one star off of my rating.