I have bought the 3-way SATA adapter before, so this was a no-brainer choice for my latest build. However, the 2-way adapter was too short for my case because the hard drive and DVD drive SATA ports did not face the same way. It's a good thing I needed another cable for my RAID, so I did not have to send it back. I ended up using a 4-way cable for a 2-drive PC. With a multi-HDD setup in a standard tower, you will have no issues with this cable, but in a mini-ITX, you could be 1" short between the drives.
PROS: Quality product, easy to use and looks good
CONS: Please bring back the 3-way adapter or make this 1' shorter
I needed this as my 3 year old computer was out of SATA power connectors but still had two available 4-pin connectors. I was able to connect this to one of the available 4-pin connectors, allowing me to connect two more SATA SSD hard drives to my computer. It worked exactly as desired!
First, this product is very cheap, even considering shipping, and works exactly as described. It's useful if your PSU has spare 4-pin connectors but no SATA connectors, and you need to connect power for another SATA drive, for example. Since it actually splits into *two* SATA power connectors, you could use this for up to two drives. My only problem is that I was mounting two 2.5" HDs (in a single 3.5" bay with an adapter) and wanted to use this one for both, but this cable has the SATA connectors so widely spaced that, I couldn't bring the connectors close enough to connect both drives, at least not with bending the wires at a really tight angle that I didn't think was a good thing to do.
Other manufacturers make a similar cable where the connectors are designed for closely-spaced connectors, so I might look into one of those instead of this is what you plan to doalthough as cheap as this is, if you have yet another spare 4-pin connector from your PSU, it'd probably work just as well to buy another of these adapters and just use one connector on each. And of course, if you only have one drive in the first place, it should be fine as well.
PROS: Inexpensive product is exactly as described (4-pin Molex to two 15-pin SATA connectors)
CONS: Difficult to use both SATA connectors if drives are close together