I built this site for a local car dealership who wanted to make their inventory information available online. The client has been extremely happy with the CMS side of things and have been happily adding and updating content for a few months now. The basics of the design weren't done by me, I just took their photoshop mockup and turned into what you see. Not that it's bad, but I could've done it better ;)
My own experience was interesting. I really love SS, it's very easy to pick up and work with to create a clean site. My only gripe is the hassles I had finding a host on which it would work! I ended up going with a host from the list of suggested hosts in the wiki. From that point I only had a few issues relating to memory exhaustion, but was able to solve them with help from the host and also the extremely friendly and helpful ppl in the IRC channel. I've been upgrading to newer version as they're released and it just keeps getting better! More stable, better performance, keep up the good work!
In future I'll definitely be pushing SS for projects that fit the mould.