It's just about the right thickness as a mattress topper, the memory element responds well and it's at a reasonable price. However, not certain that it is a Gilkey, the label says SNUGCITY. The label also says 2", which it is not, my receipt says 1", which it is not, and neither is it 2.5cms as described on the website. I'm slightly splitting hairs with the last one as I measured it as 2.3cms and, as I said before, it's just about the perfect thickness as a topper. 
One last point, it comes without any kind of cover. Just how significant this is only time will tell. Standard foam usually requires something like a stockinette sleeve over it to stop it from biting, but I think that this is not an issue with memory foam.