The DM Screen is an excellent product! I find myself looking at the screen for info much more often now than I did in 3E, because I don't have as difficult a time finding it. Furthermore, as others have already mentioned, it's ideal height, quite long, and heavy/thick/sturdy.
I've heard complaints about this product, based upon the Skill Challenge DC table presented inside, though I don't agree with those complaints. WotC not only made errata available before the product was in stores, but it is possibly the most easy-to-use piece of errata WotC has ever produced: simply print, cut, and glue it on. Done! (I'm happy that the company is willing to take these steps to correct their products!)
I was mildly disappointed that this DM's Screen didn't come with any inserts. I own the original 3.0E DM Screen, and it came with a thin 8.5"x11" booklet presenting some abbreviated rules from the DMG. I used that booklet a fair bit at the time, but sadly, there's no such insert in the 4E product. However, the main event, the DM's Screen, is superior to the 3E version in every other way.
In short, I highly recommend this product! (Now, the Character Record Sheets, OTOH...)