I have the fusion drive - when I was debating my mac it was recommended to me that it is def worth the upgrade and since I figured I was already spending might as well make it worth it since you can't upgrade later with that
I'm beyond happy..
My older computer is for the kids now and when I go back to it, it is amazing the difference! It didn't feel as though it had gotten all that slow during the years but now when I use it its a little painful since I'm so used to this one now
eta: This was a business decision for purchasing obviously so again if I was using it for scrapbooking and not design not sure I would have upgraded everything?