I am running Windows 8 and I do use the storage spaces feature on my desktop! At the moment I think its awesome that it's made its way into the consumer OS side as opposed to keeping it as a server exclusive (I have it on my server 2012 installations). My desktop setup is a 500GB SSD mirrored to two 1TB HDDs

I also use the HDDs for media files and other random crap so if one fills up I get a nice little alert then just slot another one into the bay

For the family AIO I don't have it setup mainly because I can't hot swap the internal components easily!
It is definitely beneficial and an awesome implementation of software RAID (I use them in conjunction) just make sure you have a beefed up processor to handle the copying but it's usually ok because it schedules and postpones tasks according to memory and CPU usage!