Both my rigs have screens...do I use them? Sort of...like Tab said, your ears are much faster and better telling size, depth, shape etc....You will know immediately on the first few pings without looking at the screen,.."Thats a Quarter at 6"...
A screen is good to learn with, associate certain targets to TIDs and have a 'reference point' when talking about it here...(what TID did that come in at?, probably being primary question) so it does add a bit of value in that regard for people learning what targets may be good ones or not...
Its very handy to check battery life too...
I dont look at the screen when hunting, dont have to anymore, just to check battery life...I think its easy to learn on a screened rig, then switch to a machine that doesnt have one...the quicker you ignore your eyes the better....
Its very mentally fatigueing for me to look at a screen in field on targets, seems your brain has to switch gears from your ears to your eyes and just wears out too fast...its faster and more relaxing to hunt by ear for me, plus, a guy is hunting heads up instead of hunched over watching a screen, on a sunny day the reflection will blind you too, and cause you to work a pattern that keeps it from happening and not necessarily the 'right' pattern for that piece of dirt..
Mud ...