When comparing Pixen vs Pixla, the Slant community recommends Pixen for most people. In the question“What are the best pixel art / sprite editors?” Pixen is ranked 30th while Pixla is ranked 36th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Mac native UI
Pro Supports animations
The user can create and preview animations right in Pixen.
Pro Easy to use
Pixen makes it easy for the user to start drawing and access more complex features.
Pro Tablet support
Pixen permits the user to draw with pressure sensitive tools.
Pro "Free"
Considering what you get and in comparison with some competitors, you have to say that this is a pretty inexpensive piece of software. If you use it, you are free to make a donation. Otherwise Pixla is "free".
Pro Easy to use
Clean, uncluttered interface which is a must for a tool like this.
Cons
Con Only available on Mac
Pixen is available only on Mac.
Con Not free
Con GUI
The style of the GUI might seem a little outdated, but that is a matter of personal taste more than anything.