Dominic Kay has posted some nice benchmarks for ZFS vs VxFS (1 2). He also showed the difference between managing VxVM/VxFS and ZFS. Believe me ZFS is easiest enterprise Volume Manager + File System on the market. When you've got to create few dozen file systems on an array or you've got to create some file systems but you're really not sure how much space assign to each one then ZFS is your only friend.
ps. I don't know which Solaris version was used - and it can make some difference when it comes to ZFS