What is the best? ZFS or UFS?

[simonaic]

Hi all,
I have a storage containing a Supermicro X7dvl3 with 2 intel Xeon 5110 CPUs and 8GB RAM.
I would like to create 4 volumes
> 2 RAID1 volumes (300GB 15Krpm SAS disks)
> 2 RAID1 volumes (2TB 7200 rpm SATA disks)

I would like to use NFS in order to run VM disks.
My question is :
> What is the best? Using ZFS volumes with NFS mounts or iSCSI shares ? Using UFS volumes with NFS mounts or iSCSI shares?

I know that iSCSI is best for performences but i like to manage NFS mounts (bugs/problems are easier to solve :D )

Thanks !