From March 15th, 2017 to December 3rd, 2019, 75% user give 5-star rating, 25% user give 4-star rating. for Loginas - Login as your Salesforce Users chrome extension.
As other reviews say, only works with one org at a time.. having a sandbox open in another tab will not work
Super helpful extension to support testing and troubleshooting. Currently, the extension does not support use in multiple tabs from different environments within the same org (ERROR_HTTP_400: Access Declined). It can only be active in one environment per org at any given time. This is less of a bug and more just a limitation to be aware of.
Works in Lightning!
I use this daily. Works perfectly in Classic and LEX.