Hi Treadinwell,
The comfort layers of a mattress are generally the weak link of a mattress and Talalay latex is certainly a good quality and durable material so as long as there isn’t thick layers of lower quality foam in the quilting then there should be no durability issues. The support layers of a mattress generally aren’t the weak link in terms of durability so the choice between a foam support layer (such as polyfoam or latex) or an innerspring would normally be a preference issue more than a durability issue.
You will find manufacturers who believe that Talalay is more durable and others that believe just as strongly that Dunlop is more durable but in reality they are both very durable materials and I would treat them as equals. There is more about the different types and blends of latex in post #6 here. Any differences in durability would likely depend more on some of the specifics of the mattress designs they are used to making than on the type of latex they are using. There could be many reasons for his experience and belief such as tending to use latex that is on the softer side (any softer foam is less durable than a firmer foam) or using 100% natural Talalay which can be less durable than blended Talalay in softer versions, or even the thickness of any polyfoam quilting layers above the latex that they typically use which can affect the useful life of a mattress. There is more in post #18 here and the posts it links to in reply to the same question from another member. In any case … both Talalay and Dunlop latex have a long history going back decades of being a very durable material.
Talalay is also more “resilient” than Dunlop but resilience is a property of foam that measures how high a ball bounces when it’s dropped on the material (see post #7 here) … it’s not a measure of durability.
Phoenix