I use mostly tree stands but occasionally stump sit. As far as being on the ground- I have sort of tried it at. I agree about the blinds working best for turkey and all I can figure out is the issue of scent- turkeys usually don't have a good ability to scent you like a deer or bear; if the pop up isn't completely scent free maybe it is a negative on deer, bear, etc.
I have piled dead branches, etc around me to create a blind but I think it impresses me more than the deer. In all honesty nothing beats sitting still. If you stay really still I think that is better than anything else. Years ago- before Hunter Orange, and up north, I wore a wool mackinaw in red and black plaid and had deer come right in on me. A lot of folks pick a large tree to sit against. Sometimes two smaller trees very close together work better IMHO. Finally, there are some areas that produce year after year. I generally stay away and then sneak in before dawn. The first day in such a situation is always best. Although deer are supposed to move into the wind I usually set up so that the deer comes in at a cross wind- in other words if the deer continues on his path another 20-30 yards past me- he will probably scent me. This set up also gives you a broadside shot.