Obligatory Sketch "we can do it too!": http://cl.ly/Vml2
any way sync scroll location on both PSDs?
This is how I used to work on @2x files before I had a Retina MBP. It's a great trick.
Old but gold.
Use this all the time when doing icons. I mean, I used to when I used photoshop for icons.
Been using this for years, really useful. Also great when using liveview and working at 400% on details at the same time.