This page should help some with your question on the difference between talalay and dunlop process latex, as well has having some info on latex and foam in general. https://mattressunderground.com/mattresses/comfort-layers.html
This one has more info on the general support cores. Mattress support cores - Overview - The Mattress Underground
Post #4 has some great information on durability as it pertains to latex and poly foam support cores.
As for the pillowtop question, my interpretation is that is more a factor of the material making up that portion of the mattress than anything. A good high density latex or memory foam should feel much different from the old super-soft pillowtops that a lot of people are probably familiar with from years gone past.