There's no problem when you use the included power supply with this hard disk enclosure, but please be aware that the plug which feeds power into the back of the enclosure is not wired up the same way as it was for some of the earlier Sumvision enclosures for PATA hard disks. If you already own one of these older enclosures, be sure not to mix up its power supply brick with the one from this SATA enclosure or else you might blow up your hard disk.
This SATA enclosure is a very neatly designed unit. However, when I investigated the internals I discovered that the rear panel power switch only disconnects the 5V power rail. The 12V rail remains on all the time. That's a bit cheap - who knows how the hard disk is going to react? I think I will leave the switch on all the time and turn the unit off at the mains power socket instead.
The bridge chip is JMicron JM20329 (which claims to be Advanced Format aware).