No, I'm not suggesting S2D at all, unless Microsoft would change its licensing schema for it. Datacenter licensing makes the entire idea behind S2D un-usable as of today, as much as it seems really attractive from a design point of view. I wrote a blog post on my website which is going out tomorrow exactly on this topic. It's a pity, but it's what it is.
For single nodes, can you explain me how do you see those as limits? Say I have a Cisco C3260 machine (by the way they have a configured solution with Windows plus Storage Spaces alredy), I can put in it many large HDD and some SSD. I create with this two tiers, I choose simple mirror as the desired protection solution, and here I go, I have a raid10 design. And because I have the mirror option, I can leverage integrity streams.
EMEA Cloud Architect @ Veeam Software
Veeam VMCE #1