Really does provide the support I was looking for
I was skeptical because I don't like to buy things made of synthetic materials, but I got a Purple Royal and I'm trying it out.  Here's what I like about it so far:  I sit on a futon sofa much of the day with my laptop, and the sofa is depressed where I've been sitting, so I'm sinking into the futon.  The Purple Royal is 2 inches thick and lifts me up, and out of the sinkhole, distributing weight well across the futon mattress.  It feels cool to the backside, and allows plenty of spread instead of being flattened and squinched.  I'm using it with the black cover, but I'm going to put a pillowcase over it to match the cover on the futon mattress.  Another thing I like is that I can tuck it right at the back of the sofa and it does not come all the way out to the front of the sofa; there's about 4-5" space between it and the edge of the sofa, which allows room for my legs to rest on the edge of the sofa instead of raising them up and cutting off blood flow.  I thought about getting the 2.25" one ("double") but that one has a "soft side" and I can't see any need for anything softer.  This one feels plenty soft and roomy.  I think the "simply purple" one (1.5") wouldn't cushion enough.  I will update if I notice anything different.
Rating: 5 stars