The launch pricing indicates that Samsung is not chasing the budget crown as it did with the SSD 840 EVO. That title still goes to the Crucial MX100; we suspect that reaching prices as low as that simply isn't viable with 3D V-NAND at the moment. However, this presents something of a problem for Samsung. Unlike professional level client drives (e.g. SSD 850 PRO, Plextor M6 PRO) designed for workstations and other such intensive workloads, pricing is often the most important factor for entry level ones like this and the MX100. For the vast majority of users in this bracket, all modern SSDs are now fast enough and have more than enough endurance. Samsung itself says that the SSD 850 EVO is designed for everyday computing experiences, but convincing everyday users to spend £110 on its 250GB SSD when they could save £30 and get Crucial's MX100 256GB could well be a tough sell, regardless of performance.
With that out the way, let's look now at the SSD 850 EVO family. It currently comes in one form factor: 2.5-inch SATA 6Gbps, which is still very much the de facto form factor for SSDs despite the emergence of support for SATA Express and M.2 with Intel's Z97 and X99 chipsets this year. We suspect PCI-E storage to really start taking off next year, so we wouldn't be surprised to see an M.2 version or similar then (the SSD 840 EVO has an mSATA range), but nothing is confirmed and for now it's 2.5-inch only.
=> Samsung 850 EVO 500GB 2.5-Inch SATA III Internal SSD (MZ-75E500B/AM)