Hi sawyerspath,
No the core is a thicker version of the same 2.35 lb polyfoam and it uses the same 3" of latex (your choice of firmness) on top in the zip eurotop and has the same quilting layer. If you scroll down a bit on the page you linked you will see the details of the layers in the description.
Their all latex mattress is here.
Post #2 here has a summary of the differences between the Eurotop and the Ultra Plush.
Phoenix