The problem I have with these is that they're still a bit small in terms of capacity.
1Tb is fine for the "let's lob some photos on" crowd, but my laptop alone has 4Tb of storage. In terms of putting things on for backup, I need something huge. And when you get into those sizes, then backup speed is a real issue.
These things are neither one thing nor the other. 64Gb USB sticks are dirt cheap, can be dropped and are very fast. These things are large but (comparatively) slow and fragile. Not the best for home backup.
And then you consider that pretty much any old enclosure could do if you slap the largest drive you can afford onto it. I can get a 2.5" 1Tb SSD for a couple of hundred now, but I can't get four times the storage in spinning disk enclosures for the same price.
I prefer the Zalman VE- range anyway as they allow you to mount ISO's stored on the disk and it pretends to be a bootable USB CD drive at the same time (no more carrying around boot/rescue/driver/OS install disks). One of those unique selling points that nobody else ever bothers to copy despite it being nothing but a firmware upgrade. But they can bundle some freeware backup junk that I wouldn't trust my temporary files to...