Tomm sorry for the brief feedbacks, i suffered a computer failure, and tried to respond via my mobile. I found another computer to give a better feedback. (and in men time fixed the problem, a broken power supply). Before the failure, I tried a 16bit tiff image in prophotoRGB space: a portrait of a red haired woman with some make up and quite saturated blue dress and in front of a light almost neutral gray background.
Opened this image in LR and in PS . the LR display appears a bit lighter and a touch cooler.
When softproofing with same paper profile, the apparent differnce sort of stays, the background rgb readout on a particular spot is around 210, whereas in PS it is more around 200. In shadows the rgb differences are greater and with more variation between r g and b.
But no blocking of colors or strong differences in saturated colors.
So it looks like you are suffering from a problem i do not reproduce.
I use Intel core i7 3770 and on chip iGPU, Win 7 64bit, a nec pa271w, LR4.4 and a trail of PS CS6. In LR i set the background under softproof mode to darkgrey instead of paper white to take that element out of the equation .
The NEC is set to 100lux, full spectrum, native contrast and L for trc, profiled and calibrated with spectraview2 and a xrite i1Displaypro puck.
When my printer (epson4900) is back in my office this weekend (i hope) i will experiment a bit more, i normally do not use PS, so whenever i need to go to PS i ask a friend to do the mods in PS. But habe a trial now to see if it is worthwhile to have it myself.
I remember reading in a book written by Martin Evening that LR and PS have slight display differences, have to find that book and chapter.