I have Solaris on my home server, used OpenSolaris and OpenIndiana for 3 years. They're nice OS until Oracle killed the OpenSolaris project and left them orphaned. Currently, they're nice OS for now but what about 5 years in the future when Oracle's Solaris is further ahead of OI, OmniOS and all others. They're fine for hobbyists but not for production server where support is essential.
By that time FreeBSD and Linux will be further ahead of OI and OmniOS since they are relatively new to the OS arena. It's a wait-and-see approach whether they'll survive and whether they can recruit more developers to keep the project alive. I've seen too many OS come and go.
Oracle said they'll release the code after Solaris 11 release but they haven't in the last 2 years and it clearly showed that they have no intentions of doing so. Oracle made a big mistake to kill the project and they could continue to actively support it while charging customers for support just like Red Hat. So, I'm not going to use OS on a production server without any serious backing by a company, developers or community support.