For years, I have softproofed in CS and printed from Qimage. I recently bought LR4 and CS6. In CS, my routine was to do a proof setup with the correct profile and best rendering intent, duplicate the image, go back to the softproofed image and use adjustment layers to optimize the image for printing. I would then go to Qimage to print.
Since using the softproof capabilities of LR4 I don't softproof in CS any more. I select SoftProof in LR4, and click on the before/after (x/y) icon to get the same setup as in CS, with one click. LR4 fades in the white border, set to "paper white," which bypasses the "Make Your Picture Look Like Crap" routine. I find it easy to correct the softproofed copy in LR4, and I have set up some presets in the print module which makes the process easy and efficient. However, I still prefer to print from Qimage for several reasons, so I set up a Edit In preset in LR4 that sends a softproofed, corrected copy of the image to Qimage.
I am now used to the softproofing in LR4, and would be very unhappy if I had to do it in CS6 now.