Are you kidding? I've found that Illumos is not at all friendly to white-box hardware. Examples:
Some 2-port AHCI cards mysteriously fail after a random amount of time (oops, there goes my L2ARC device until I reboot).
AHCI hot-swap on my motherboard SATA ports is a game of Russian roulette. I'll randomly get write errors on other drives when I slot a drive in. At least hot-swap worked well on my SAS HBA.
Hardware sensors that work fine with lm_sensors on Linux are not at all usable on Illumos, which expects IPMI.
KVM on Illumos? Not if you have an AMD CPU.
A couple of weeks ago, I finally ditched my home OpenIndiana system (was running 151a9) and threw CentOS 7 on it with ZFS from the official ZoL repo. Yeah, it has systemd. So far, I've found that systemd isn't any worse than SMF; I can live with it. Things that wouldn't work in OI work nicely on C7. The ZFS pool imported without a hitch, though I had to rework my sharenfs options and do a little tinkering to get sharesmb to work with Samba. It was worth the effort. I no longer need to use crazy ACLs to get my shares to work as expected, another plus. I might try later to run a ZFS root, but for now I'm using MD-RAID mirrors for the OS itself.
Aside from the better hardware support, a big advantage of CentOS is that I don't have to worry (as much) about something breaking when I update the system. OpenIndiana's new Hipster approach is fine if you're the type who would run Debian Sid on a server, but that's not my style. Add to that, there's no clean upgrade path from 151a9 to Hipster.
I wish them well, but my foray into Solaris-land is over.