BTRFS has the same characteristics, but is FAR FAR MORE MATURE on Linux.
It makes no difference if the filesystem is mature on solaris. This has no relation to its level of maturity on linux.
You can use NTFS to compare. One could consider that NTFS was mature all the way back in 1993. Linux kernel 2.2 had the beginnings of NTFS support starting in 1999 -- was it suddenly a good idea to run your enterprise linux servers on NTFS all the way back in 1999? NTFS-3G wasn't considered stable (aka "safe") until 2007 -- 14 years after NTFS was introduced, and yet people STILL don't put their enterprise linux servers on that filesystem TODAY.
Must remember that it is a different platform. You can't just magically and instantly dump in code and expect it to work the same as what its emulating. It takes years to work out the bugs and stabilize it. Why go to all the trouble for ZFS when we have BTRFS that is so much closer to being enterprise ready? Even major distros like Fedora are talking about making BTRFS into the default filesystem for new installations AS SOON AS AUTUMN THIS YEAR. I would imagine that if this happens and works out, the next version of RHEL will follow in a few years -- that will be enterprise linux servers on BTRFS, well before ZFS is even ready for bleeding edge distros.