It's just a different animal, imho. The neat thing is if you have one drive fail you lose nothing. If you have multiple drives fail, you only lose what is on those failed devices. It's not striped so a URE can't kill your entire pool.
Unfortunately WAY overpriced for what it is, imho. I've never made it much past a quick eval for that fact. It seems like a nice toy for someone that wants more than no protection on a disposable media collection and doesn't want to learn anything too complicated. Also mostly suited to low performance uses. I can't imagine a business use when things like zfs exist, or even mdadm + lvm.
FlexRAID and snapRAID are a couple other homestyle tools to look at in the same vein. Seriously though, once you taste ZFS you won't want to leave. She might be a bit demanding, but hard to compare to anything else.