Depends on what you are working on. Sometimes you will work with designers who need text and on-page elements to line up in certain ways or provide a certain am

Depends on what you are working on. Sometimes you will work with designers who need text and on-page elements to line up in certain ways or provide a certain amount of interactivity. In those cases REM can be a huge pain when you have to design everything in relation to everything else rather than just be able to pull over the design verbatim.