I became aware of the 'problem' of LED monitors flickering thanks to this YouTube video.
This video put me off buying said monitor, and I recently purchased a ViewSonic VX2370Smh-LED 23" for a decent price.
After doing a bit of further reading I see the 'problem' is caused by lowering the brightness on an LED LCD monitor (and how the tech works to do this) and isn't specific to this Dell.
I've used my phone camera to look at my monitor and I see flickering similar to the YouTube video on the monitor I have bought.
Now, I don't seem to obviously be able to detect the flickering with my eyes directly, but I've done some reading and some people say this can cause eye strain, etc.
My eyes do seem to feel more tired when using the new monitor but I believe this could be A) Because I've read about the issue and the effects it can have B) I've gone from a 19" to 23" screen with brightness higher than I usually use (as I believe this causes less flicker from my reading).
I'd be really interested to get any opinions as I am half tempted to return the monitor, and surely it has implications for many people who use these monitors if its all true.