The pillow's nice but it's very firm and I immediately noticed my bed (a Sleepy's brand bed that cost me $800) was a lot more saggy than I thought
I'm looking into the Shikibuton because it's (apparently) extremely firm, whereas my bed is ... firm. With a pillow top. But it seems to be much, much firmer at the 2 feet around the edge, and very ... odd ... lumpy? ... elsewhere. It's 1 year old and I've turned the mattress now and then.
I used the pillow on the floor and that was actually nice. Typically I never remain in the same sleeping position for more than 2 minutes. I kind of coma'd; it worked out well.
Other stuff I've had is Wal-Mart cotton filled pillows; down pillows; very ... not-firm beds (bouncy springs!); Latex International rubber pillows (spoiler: they suck)... when I was shopping, I tried the memory foam stuff (HATE, every time I tried to shift it was like a World's Strongest Man competition! How do you escape that death trap in the morning?!).
I'll report on the Shikibuton when I pull that trigger, which is not yet; dropping my car loan from 10.71% to 2.61% first, aggressively paying down balance for the refinance as I want a lower payment.