I did some benchmarking a while ago on freebsd7 solaris10 and centos4.6, all on the same hardware. At the time, Veritas came out quite well.
on 8 disks, raidz/5:
FreeBSD7: 144/73 MB/s r/w using dd
Fedora7 md raid: 164/130
FreeBSD7 (zfs): 236/155
Solaris10 (zfs): 169/132
Fedora7 (md0): 259/188
Solaris10 (zfs) random write was as fast as veritas and much faster than all the others (~300MB/s versus 150-ish).
I'm now running btrfs and am quite happy with it, should probably run those benchmarks again and clean up the page a bit http://www.crystalconsulting.eu/bench/