Up until not too long ago, it seemed like if the leading proprietary tool was half baked, the open source tool was a quarter baked. Take office suites. OpenOffice was pretty consistently ten years behind MS Office. Or GIMP was constantly lagging behind Photoshop in usability, but now is a very good photo editor. The exception has always been development tools, where you get a nice confluence of motivation to volunteer and people knowing what they want.