While the lack of an optical low-pass filter means the D800E can capture more fine detail, it also opens the camera up to the risk of moiré artifacts appearing in its images. We should make clear that this isn't a camera fault, it's just the way the technology works, and Nikon openly warns photographers on its D800E site of the inherent pros and cons of the camera: "Slight increase in sharpness and resolution with increased occurrence of false color and moiré." There are even sample images to show just what moiré looks like.
The D800E is also not the first digital camera without an optical low-pass filter. The Leica M9 and S2 cameras, the Fujifilm X-Pro1 and medium format cameras eschew the filter in favor of higher resolution. We were curious as to how bad moiré would be with the D800E, so we took it out for a day of shooting as many fine, repeating patterns as we could find. What we found was surprising, in about 200 shots we saw about three with visible moiré patterns, when we thought there would be more. In some subjects we were certain that moiré would appear, only to find the shots perfectly clean.
You'd notice that there appears to be moiré patterns in more than just one of the images shown. But we don't call them out because they don't exist in the original files when viewed at 100% - it's just a combination of re-sizing the image and the limitations of display technology which causes this effect to appear. We had the same experience when looking at some images on the D800E's LCD - some of them look like they have moiré but once we zoom into the image they disappear - it was the LCD, not the image, which was creating the artifact. The only way to really check is to look at the photograph zoomed up to 100%, or to print the photograph out.
It's quite clear that the D800E provides a higher level of fine detail than the D800, but there's a risk involved of having moiré show up and ruining your shots. But there were far less moiré patterns showing up than we thought we would encounter, especially when we were specifically out shooting for it. Still, whether or not you will benefit from the D800E's higher resolution depends on your own output needs. At lower display resolutions, it's quite doubtful that anyone can tell the difference between a same image shot with the D800 and the D800E.
If you're worried about the appearance of moiré, then you can save yourself some money getting the D800 which costs S$4488 and already gives you a lot of resolution, instead of the D800E which costs S$4988. But if you shoot for large prints, and shoot subjects with low chances of moiré, then perhaps the extra S$500 is worth it for the clear-seeing D800E.