If you're looking for good value, I'd pass and not buy the Fusion Drive.
Steeped in Apple's marketing magic & clever naming, it has its place if one has unlimited funds.
Speed is greater, but only under certain conditions like so many other components. The day to day difference I've noticed with my fusion drive, reveals it to be less than a good return on my investment.
That's not a complaint, as I have years of experience with Apples highly hyped creations. Therefore even before I chose it, I knew the risks involved. Even though I buy a lot of Mac computers & gear each & every year, this will be my first & last Fusion Drive.