I thought about getting one of those dual drives to replace the 1TB spinner in my laptop. After some investigation, I decided against it. The 2 drives share the same SATA connector and the machine will only see the ssd side until some proprietary WD software is loaded to enable the machine to see and access the hdd side. Because the 2 share the same SATA port, performance is hindered when the system needs to access both sides of the dual drive at the same time. The included ssd is not a particularly high performance drive and the spinner portion is only a 5400rpm drive.
I ended up going with one of these: Samsung 840 EVO 500GB
. Less storage, yes, but I felt 500GB was all I needed for a laptop and this drive perfroms better than the dual drive. I also got a killer deal, $209.25, including an extended warranty. On top of that, I had a $200 gift card so it only cost me $9.25 out-of-pocket.