I use Inkscape from a long time, and it's generally a very good experience. The only thing I tried to do recently that didn't work was to open an .eps file provided by Google (the official Google Play button - they do not have .svg files, but even Apple has for their App Store). It couldn't directly open the file, I searched for tools to convert it but nothing worked. The only program that could open it was Adobe Illustrator, from there I could export it to .svg. I'd hope Inkscape could open .eps files AND Google to provide a open standard format for their vector files.