Edited: I've had it for less than 3 weeks and there is a visible indentation where I sleep.  Even with all the layers on top of it.  I weigh 135.  Probably better to spend more for something that will last longer.  Going to use this for dog beds.  
Old review: Good product for the price.  It is the right firmness for what I was looking for.  I took off the layers from my pillowtop mattress due to indentations and put this as the new base layer, then a 3" latex topper, then a new pillowy top to keep it all together.  Very comfortable bed again.