A good summation on SSD and application in use with a 2nd HD
SSD vary in failure frequency and although the spec on read/write life has increased their still is a limit and the limit is even lower on the new Samsung 840 over the 830 due to the NAND technology they use. A regular HD will typically give plenty of warning of failure or problems. Whereas an SSD can stop cold turkey and they is very little that can be done. Data is all gone. Anyone using one should or rather must have a drive the backup to and image the boot drive to often. Failure to do so will get you. Its a matter of when not if. There is little redundancy in an SSD most don't play with SMART technology that HD have. Sandforce controllers which are widely used all be it with different firmware are amonst the most troublesome. Marvel controller are consistantly more reliable but don't have some of the high performance numbers but its results are consistant.
Reliability is my first criteria for storage and some backup such via eSATA is fast and reliable to external drives in the Terabytes is simple to keep photo's music and images of the boot SSD on in the event of faiure a new drive can be rebuilt fairly quickly. At least in comparision to a clean install and updates from MS and app installs which all easily will take a full day if not more. The image solution is a few hours typically depending largely on the interface used. With USB 3.0 being new and machines with troublesome drivers I would not put too much faith in that interface when it comes to recovering and image or validating that corruption had not occurred.
This is of course my opinion and have been in the industry for decades.