Hi Stine,
In very general terms … smaller local or regional manufacturers will tend to use higher quality materials in their mattresses than their larger competitors but this is very general and some smaller manufacturers can be exceptions (see post #4 here and post #12 here). Even manufacturers that use higher quality materials in their mattresses generally make some mattresses that use lower quality materials so I place more value in the transparency of a manufacturer than on more “generic” comments about the mattresses they make as a whole. While many of the better manufacturers are only available locally or regionally and my comments about them would be in the many local lists around the forum … you can see some comments about the top 15 manufacturers that are more widely available in terms of their transparency in this article. More transparent manufacturers will often use better quality materials which is one of the reasons they are more transparent (they want their customers to know what they put inside their mattresses).
The overall amount of foam in the comfort layers is a matter of personal preference so there isn’t an “ideal” amount of foam in terms of thickness but you are correct that the quality/density of the polyfoam in this mattress is low. Having said that … it’s also on the edge of the thickness range of “about an inch or so” of lower quality or unknown materials in the quilting layers which would be more durable and have less effect on the useful life of the mattress (see the guidelines here). Unfortunately they don’t provide much specific information about the 2" “eco fiber pad” including the type of fiber or whether it is densified or its specific makeup so I would be cautious here because fiber materials can tend to compress and develop premature impressions … especially in combination with 1.5" of low quality/density foam.
If you let me know your city or zip code I’d be happy to let you know of the better options or possibilities I’m aware of in your area which can give you a good starting point to find some additional local choices that may be in the same or better quality/value range. If you are also open to online choices then some of the better online options in a lower budget ranges are listed in posts #3 and #4 here (for latex and latex hybrids) and in post #4 here (for other types of mattresses).
Phoenix