I chose this topper for our mother-in-law suite, we have a california king that is very firm and my parents were having some pain sleeping on the mattresses. I got this gel memory foam topper and after just a few days using it, they both said that they were getting better sleep than they had in quite a long time. It's soft and responsive but not too thick that you sink in too much. I did let this topper air out for 48 hours before placing it on the mattresses and making the bed. I did not notice much of a smell during that time period which was very nice as some memory foam has a strong initial scent. Overall very pleased with this topper, it definitely helped give some relief to my parents so I'm grateful for that.