While 2.5” units are most common by now, M.2 SSDs will be popular in a near future, since most motherboards are coming with a slot that complies to this new standard. The flexibility of this format is a plus, since is compatible with devices that use other standars than the SATA-600, such as as thr PCI Express.
The Kingston SM2280S3/120G is one of the first M.2 SSDs on the market, and our tests showed that it is not bad compared to the more popular 2.5” counterpart.
Actually, the fact this unit comes with a memory chip as a buffer and uses a controller that does not rely as much on data compression as the SandForce controller used in the V300 makes the SM2280S3 faster than its more popular cousin in some tests, specially on write tests with uncompressible data.
Since the Kingston M.2 SSD model SM2280S3/120G is faster than the entry-level traditional 2.5” SSD from the same manufacturer, we can say it is a good deal if your motherboard provides an M.2 slot.