How important is an LCD screen on your streamer?

I use critical mode on my Aurender NS200 and the screen is always off. Honestly everything you need to see is on your tablet or phone.

Willywonka hit it.  I control my streamer from my iPad and NEVER look at the streamer.  Truly, never.  

I never looked at the screen on my Aurender N100SC except to make sure it was turning off properly.

With my Eversolo devices you cannot configure some stuff without looking at the screen but after configuration is complete the iPad is so much easier to use.  If the device could use Bluetooth and allow everything from the iPad that would be best IMHO.  The device is almost 20 ft. from my listening position so I cannot see anything anyway, I got a bad neck ache setting up the thing!

Screens emit EMI, which is largely your digital source's worst enemy. Keep them off as much as you can to lower the noise floor and hear your system perform at its best rather than seeing what is playing.

And I don't know what you're talking about with regards to Aurender. They have some of the biggest, clearest screens on the market on all of their products. That said, as others mention, they have options to turn them off, and most people do this because of the reason I state above.