When comparing Inkscape vs Krita, the Slant community recommends Krita for most people. In the question“What is the best open-source drawing software?” Krita is ranked 1st while Inkscape is ranked 2nd. The most important reason people chose Krita is:
Krita is completely free and open source. They have raised a couple of successful Kickstarters in the past to get the initial financing and now they are accepting donations.
Specs
Question Ranking
Pros
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.
Pro Cross-platform
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.
Pro Free and open source
Krita is completely free and open source. They have raised a couple of successful Kickstarters in the past to get the initial financing and now they are accepting donations.
Pro Easy to use layout
All the most used and useful tools are easy to find in Krita's UI and are often just one click away. They are not hidden behind menus or dropdowns.
Pro Amazing support for displaying brushes
Krita's preset brushes are one of the default dockers. Each brush has a preview on mouseover that shows a detailed view of the type of brush involved. All the brushes also have useful and descriptive names such as "HP Pencil" or "Textured Fuzzy".
Pro Very customizable
Although the UI is rather busy, Krita is very customizable. The editing window can be themed and the sidebar can be customized extensively throw many dockers or panes.
Pro Easy editing in a tiled view
Tiled view that shows your image tiled in the editor, and permits you to edit it as you are seeing it tiled. If the brush passes out of your texture, it will just automatically wrap back the painting to the other side of the original texture, while permitting you to paint and see the results on any of the tiled "clones" (the shortcut key to activate this is w by default).
Pro Constantly updated
Krita is getting constant releases with updates and bug fixes. New features are added at a pace that far surpasses the other alternatives.
Cons
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.
Con Unstable
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.
Con Poor Touch Controls.
They are still pretty much a WIP. But they are getting there.
Con Working with text is not that pleasant
Con Documentation is lacking
Krita's official documentation is incomplete in some areas, especially for new features that are constantly added. But this is compensated with it's great design and usability which makes it easier to understand how things work.
Con New features are not tested thoroughly
Since releases are so often and with little time between them, usually new features are not tested a lot and this can bring a lot of bugs with them. Which fortunately are quickly patched in the next release.