Hi jim1952,
The thickness of a mattress doesn’t mean a great deal by itself and the extra 2" of polyfoam is wouldn’t be that significant in terms of feel and performance for most people although the polyfoam in the Eurotop is higher density than the Cotton Camilla which is a value “plus” for the Eurotop.
All of them have similar comfort layers but the Bamboo Bliss has wool quilting which is a more costly and significant addition to the mattress while both the Cotton Camilla and the Eurotop have polyfoam quilting so they are closer in their overall construction. The Cotton Camilla also has a more liberal and less costly exchange policy and is a little less.
Each person may have their own “personal value equation” of course and can have a different set of criteria that is most important to them and while none of the three mattresses are exactly “apples to apples” comparisons and are not exactly equivalent to each other … if you consider all the pros and cons or each then IMO the Cotton Camilla would be closer to the Eurotop overall and would probably have better “value” as well for an online purchase if you factor in the possibility of needing to exchange a layer and the costs involved to do some fine tuning.
Having said all that … all of their mattresses are great quality/value and in overall value terms would be fairly equivalent in terms of value so my comments weren’t about a major “value” difference. The similarities of construction and lower risk of the Cotton Camilla though would probably tilt the scale for me (depending on how much confidence I had in my comfort choice) because one of the things I encourage people to be aware of with an online purchase is to consider their recourse if their comfort choice isn’t as “ideal” as they hoped. None of their mattresses would be a “mistake” though so the comparison is really between “good and good” and of course others may have a different set of criteria and a different assessment of the pros and cons of each.
I probably should have added an “IMO” after the comment 
Phoenix