How important is an LCD screen on your streamer?

I agree with those who say the screen is unnecessary and adds to expense and impairs sound quality.

I have universal disc players in my systems.  In my main system, if I turn off the video circuitry of the disc player, I hear more deep bass if the material I'm playing has it.  Since all my universal disc players have this option, I think that video circuitry can impair SQ, and I suspect that is true for displays (on some of those players, turning off the video also turns off the display).

Bottom line is I love having a display to go along with what I am playing.  Need not be on the streamer itself, though a nice feature if so.  For example, displays in Roon are awesome, for example using a browser on the 60" smart TV.  My whole family will listen then as well especially when dynamic lyrics for singalong are displayed for songs they know.  Built in streamer screen is too small for that.

SO displays are a big + in general for me.  Having on on the streamer itself ....nice feature but there are better options.  

Same opinion here.  I use a Lumin U2 Mini.  It has a pretty basic OLED display, no album art or anything.  Most of the time I turn it off because my aging eyes can't read it from across the room anyway.  I use Roon, so there's really no need to display anything on the streamer.  Anything I want to delve into is right there on my iPhone, iPad, etc.

Not important, but a cool feature to have. I like displaying the album cover. 

Not important unless I'm checking to see that the bit rate from Roon is actually going to the streamer.