Straight 800 here. I didn't see a real advantage to the 800E. In situations where you have to post-process out the extra aliasing and moire, you stand to lose more detail than if it were mitigated optically. The 800 makes more sense for the widest variety of shooting situations. 800E could have a small advantage if you are always in controlled situations or have complete control over what sort of detail you're always shooting.
My D800 is going to be used mostly for long-exposure and time-lapse work. But also for general stills shooting when I want the full-frame sensor size and/or I don't mind the larger camera, but maybe still don't want to use the EPIC.