When comparing ARC Welder vs PrimeOS, the Slant community recommends ARC Welder for most people. In the question“What are the best ways to run/emulate Android on a PC?” ARC Welder is ranked 5th while PrimeOS is ranked 8th. The most important reason people chose ARC Welder is:
Even though it's a developer preview, it's likely to evolve quickly as Google is developing it. Since Google is also behind Android, it makes sense to use a more official way of running APK. If they don't work, you may check with the developer so it may eventually work.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Developed by Google
Even though it's a developer preview, it's likely to evolve quickly as Google is developing it. Since Google is also behind Android, it makes sense to use a more official way of running APK. If they don't work, you may check with the developer so it may eventually work.
Pro Cross-platform
Works on Chrome 41+ on Windows, Mac, Chrome OS and Linux.
Pro Allows running apps in a Chrome web browser
It installs as a Chrome App and runs on most operating systems (Windows, Mac, Linux, Chrome OS), even thought x86 support will be put in maintenance mode soon.
Pro Dual boot at single click with PrimeOS installer
Pro Standalone OS, better performance than any emulator
PrimeOS is standalone OS thus provides 2x performance than any emulator as emulator runs on a host OS.
Pro 3x better performance than windows budget laptop
Pro Android Gaming on PC
PrimeOS is equipped with a key mapping tool, DecaPro whihc let you play any Android game at the comfort of keyboard and mouse.
Pro Android Ecosystem with Desktop Interface
PrimeOS provides access to the whole Android ecosystem with complete desktop interface. Now use multiple apps on single screen with minimise, maximise and close option.
Cons
Con Discontinued
Discontinued after December 2020.
Con Not all Google Play services are yet supported
ARC Welder supports OAuth2, Google Cloud Messaging , Google+ sign-in, Maps, Location, and Ads APIs from Google Play services.

Con Only supports "arm" apk files
"x86" apk files don't work as of 20150422.
Con Keyboard input is spotty
Con No accelerometer emulation
Con Orientation mode has to be selected before running the app
Con A single app can be loaded at a time
Con Windows software aren't compatible
