When comparing yEd vs Inkscape, the Slant community recommends yEd for most people. In the question“What are the best flowchart / diagram softwares?” yEd is ranked 4th while Inkscape is ranked 5th.
Ranked in these QuestionsQuestion Ranking
Pro Completely free
Runs on Windows, Linux and Mac OSX. There also is a Web application.
Pro Automatic Layout
With automatic layout you get great looking diagrams with very little effort. yEd has the most versatile and most complete collection of automatic layout algorithms.
Pro Free and open source
Inkscape is GPL-licensed and maintains public repositories.
Pro Opens lots of file types
Inkscape supports many common formats for import (including SVG, Photoshop and Illustrator) and its plugin architecture allows more to be added.
Pre-built binaries are available for Windows, Mac and Linux. Inkscape can be built from source on additional platforms.
Pro Export to different file types
You can export and save your files for example as a "normal" svg, png, jpg, bmp etc. file.
Pro Integrates well into a X11-System
Its uses the X11 icon theme and desktop theme(GTK).
Pro It's really easy and fun
You can edit and create vector graphics with Inkscape.
Con Not free-as-in-freedom
Not released under an open-source license.
Con Very slow startup on some systems
Depending on factors like how many fonts you have installed, Inkscape can take upwards of 30 seconds to launch.
Sometimes it just crashes without any reason, so it's not really usable as professional application.
Con Based on the GTK widget toolkit
Software is based on GTK, so it might not integrate well in non-GTK environments. It also requires many dependencies on those non-GTK desktops. It also adds dependencies to GTK-environments since it is written in C++ which requires the gtkmm wrapper/interface
Con Uses its own SVG-format by default
Inkscape might use SVG as its default format, however this SVG's contains some additional SodiPodi/Inkscape additions that can be troublesome if you want to import the SVG into some other application.
Con Mac version is in worse shape than Windows/Linux version
Con Incompatible with previous versions
Sometimes backward compatibility breaks. For example, pre 0.92 SVGs are incompatible with later releases (due different default resolutions).
Con Y-axis inverted
0,0 coordinates begin in lower left corner, not upper left corner as SVG standards define.