Hi orkan,
While other people’s comments or reviews about the knowledge, service, and guidance of a particular business can certainly be helpful … I would avoid 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 (see post #13 here).
When you are making an online purchase I would put a lot more trust in the trial period so that you can confirm a mattress is a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on your own experience regardless of how anyone else may feel on the same mattress).
If the Tuft & Needle does turn out to be a “good enough” match for you in terms of PPP then it also uses good quality and durable materials so there would be no weak links in the mattress that would reduce the durability or useful life of the mattress unless you are in an unusually high weight range (around the mid 200’s or so or higher).
Phoenix