Most highly compresable things like down jackets, sleeping bags, insulation layers get stuffed. Tents, tarps, pads get folded the minimum amount of times to fit in the desired space then rolled up tight.
I very rarely use any sort of stuff sacks. My pack simply acts as one giant "stuff sack" with everything stacked inside, in approx. order of use.
I have heard that stuffing it preserves both loft and dwr finishes, because the insulation doesn't get compressed the same way over and over, and the fabrics don't get repeated creased the same way, wearing the DWR in those areas.