Decision: Dlink DNS-321 vs HP mv5140

[upsidedown]

I know there are many choices, but the choices I have are between these two. I have read the reviews (SNB reviewed the mv5150). Any thoughts from actual users?

I would have two 500gb drives in the Dlink so capacity would be the same. the Dlink is slightly faster, but not sure it will matter in real world.

The NAS will be used for home backup and media libraries.

Thanks