Hi Bob
Have not visited this forum in a long time and some recent activity on my part prompted me to look in on the "old" gang.
As you know I have the Pentax 645D, the D800E and the now the D7100(a great camera by the way) but i have been disappointed by all of them with a satin white dress in the sun next to a black tux in the shade. The classic situation the S3-S5 sensor was designed for. So in the last two weddings I brought one of my S5's just to see what I would come up with.
If you look at the DR of the D800E or D800 the specs and tests say that you get as much DR as the S5. Well yes and no and that no is a resounding no by the way. Indeed you can get as much DR from the D800E as the S5 but you have to under expose by as much as 2-3 F stops to get it. When you underexpose by that much you have to fight grain and believe me, shadow detail is a very tricky thing to get right while holding highlights when you have underexposed by that much. Moreover just how far under did you go when you shot it at -3. Some situations give you as much as -4 or even -5 because your meter is not very accurate when you are underexposing by that much. As most of us know with the S5, or S3 for that matter in RAW, you just shoot and get normal looking exposures on the LCD, look at the histogram and if you are in the ballpark you will get good detail in the shadows and you have almost infinite immunity from blowing out the highlights. With the Pentax, the Nikon D800E and the Nikon D7100 if you do encroach on too much light on peoples faces good luck in finding a good color balance on skin tone. You get a yellow-orange sick looking skin with some areas of pure white and all you can do is make it into a black and white. The shot is blown and you are better off deleting it.
OK, on resolution the S3 and S5 are not where they need to be although for wedding work they work nicely.
I have said it before and I'll say it again even though I know it makes absolutely and completely no difference to anyone, what I would love to have is a full field camera with the S5 sensor laid out to be full field which would make it about a 14MP camera. Files would be big but so what. I would love to have that capability and it is too bad Fuji didn't see fit to build it.