I've used it for Linux systems, and that thing wasn't easy ported to FreeBSD. It doesn't do partition dumps, it understands the filesystem, compresses all the files to archives and writes down partition info somewhere, so if you restore from a fully-partitioned 100GB HDD to 200GB one, your partitions will be recreated twice as large. The bootable restoration media is created as a live CD with same kernel and essential userland parts of the system that ran backup generator, ensuring that same computer can boot the backup CD without hardware/driver problems. Eg. on Linux it picks up the running kernel/initrd, and userland tools that it needs to perform restore. This stuff is completely different on FreeBSD.
Thus if they market FreeBSD as supported platform right on their frontpage, I say it should work. Anyways, good program that saved me a lot of time - like perfectly replicating a system from a hardware based RAID/SAS branded server to single SATA $200 mini-ITX box, in under a hour.