Hi cinn,
Hopefully some of the forum members that own a Casper will see your post and share their comments but I would be very cautious about using other people’s experiences or reviews on a mattress (either positive or negative) or review sites in general as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you and in many if not most cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person or even a larger group of people may be completely unsuitable for someone else to sleep on (even if they are in a similar weight range or have a similar sleeping style) and reviews in general certainly won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here).
While I can’t speak to how a mattress will feel or how different mattresses will compare in terms of comfort and PPP for someone else … outside of “comfort” and PPP the most important part of the value of a mattress purchase is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t “feel” and assessing the durability and useful life of a mattress depends on knowing all the specifics of its design and construction and the type and quality of the materials inside it regardless of the name of the manufacturer on the label (or how a mattress feels in a showroom or when it is relatively new) so I would always make sure that you find out the information listed here so you can compare the materials and components to the quality/durability guidelines here to confirm that there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
You can see some comments about the quality of the materials in the Casper along with many of the other simplified choice online mattresses in post #2 here in the simplified choice mattress topic. A forum search on Casper (you can just click the link) will also bring up all the comments and feedback about it on the forum.
If you are in more average weight ranges then there are no lower quality materials or weak links in the mattress that would be a cause for concern relative to the durability and useful life of the mattress although I would be cautious if you are in a higher weight range (more than the lower 200’s or so) because of the 4 lb memory foam and the 1.8 lb base layer.
Phoenix