Hi Joseph,
 
Thank you for your question. I have looked at this mattress and as you say there is no GSM which makes comparisons nearly impossible. This mattress is a one-sided mattress with natural fibres above micro HD spring above orthopaedic support springs and with man-made fibres below.
 

 
The micro HD springs do not offer any support but do put up the spring count and take up space where more upholstery could be. Unless your body weight(s) are over 16 stone you would not even need a firm spring tension let alone orthopaedic springs. If you do not weigh enough to compress the springs then they are not giving you support.
 
The natural fibres in the top layers do offer a cooler sleep surface, are more breathable and longer lasting than synthetic fibres. Having said that, as this mattress is a no turn mattress you are not going to be able to prolong the life span of the mattress by regularly turning over the mattress which helps even out the natural settlement all mattress have.
 
[recommended-product post="626274"]
I would recommend looking at our Artisan 1500 which has firmer medium upholstery layers that contain 53% natural fibres. The springs in this mattress can be selected to suit your body weight to give you the correct level of support and as it is a two-sided mattress, regular care and maintenance will prolong the lifespan.
 
I hope this is helpful and if you would like any further information please do not hesitate to contact the office on 0161 437 4419.
 
Kind Regards
Michaela