Every pool deck conversation in Brevard starts the same way: it gets too hot to walk on. That is a real, measurable difference between materials, and it is worth understanding before you choose.
Travertine is natural stone with a porous structure that holds noticeably less heat than poured concrete, which is why it has become the default premium pool deck here. It is also naturally textured, so it keeps grip when wet, and it can be cut into bullnose coping that finishes the pool edge cleanly. The trade-off is that it is stone: it will take an oil or rust stain if you leave one sitting, so it wants sealing on a schedule.
Porcelain pavers are the newer option and they are technically impressive: dense, effectively non-absorbent, colorfast under UV, and available with high slip ratings. They stay cooler than concrete, resist staining better than travertine, and they look identical in year ten. They cost more, and they demand precise installation because the material is unforgiving of a sloppy base.
Concrete pavers remain the value choice and they are perfectly usable around a pool, especially in lighter colors that reflect more heat. They cost less, they come in every shape, and a damaged one is trivially replaced. They are simply the warmest of the three in direct August sun.
Color matters as much as material. A light travertine and a light concrete paver are much closer in surface temperature than a light travertine and a charcoal one. If heat is your main concern, look at the lighter end of whatever family fits the budget, and see a real sample in full sun before you commit.