Is a cache warmer worth it?

I have been doing some site speed testing on my site using gtmetrix. The first time I do it is normally pretty slow, but after a few times I see drastic improvements and I figure that is because it is getting cached somewhere. Will something like a cache warmer like- https://amasty.com/full-page-cache-warmer-for-magento-2.html or https://mirasvit.com/magento-2-extensions/full-page-cache-warmer.html give me that same time of performance increase?