Some M.2 SSD’s are designed for the PCIe connector, which has far more potential than the previous standard for SSD's, SATA. Add that to the sheer difference in speed of SSD technologies, and you’ll find that reasonably priced M.2 SSD’s can fetch you 15x the speed of the fastest hard drives.
You’ll also be able to find some M.2 SSDs that take advantage of the NVME protocol, which offers much lower latency.
Operating systems such as Windows utilize your computer's storage all the time, so an upgrade will make everything feel smoother. The difference will also be evident in the improved computer boot times and shortened video game load screens.
2. Compact Form Factor
M.2 has actually been used as storage in notebooks and laptops for years, but, we never saw the speed difference because it still used the old SATA connectors.
Typical 2.5 inch SSDs are about the size of your entire hand, but most M.2 SSDs could lie on two or three fingers. Better yet, M.2 connectors plug right into the motherboard, so there’s no need for extra cabling.
M.2 drives reduce the weight of SSDs from 50g to around 7 grams, about the weight of a leaf on a tree.
If you’re making a portable build, then an M.2 SSD should be a serious consideration to reduce space and weight.
3. It's the future
All three innovations, M.2, PCIe storage and NVME, are all expected to dominate the consumer market in a few years.
We’ve seen new M.2 projects come out of all the major storage manufacturers, including Samsung, Intel and Western Digital. If you get your hands on a computer that supports M.2 drives, you'll open up plenty of upgrade options in the years to come.
4. Just as reliable
One of the key advantages of SSD’s over hard drives was that they don't physically degrade and often last longer. M.2 SSD’s work in the exact same way, so unlike many new technologies there’s little long-term risk and their reliability is well known.
For most consumers, the peak of the price to performance curve is at the 2.5 inch SSD. Unless you feel the need to stay on top of computer performance or have a specialist application, it might be better to wait.
M.2 prices have only recently become reasonable for the upper end of the market, so it’s a few years yet before we see faster technologies take over.