The MX200 will be available in three flavors: 250GB ($140), 500GB ($250), and 1TB ($470), and offers sequential read and write speeds of up to 555MB/s and 500MB/s (and random read/writes up to 100k/87k IOPS) at all three levels. Compare this to the MX100, The Wirecutter's current favorite SSD, which sports 550MB/s read speeds at its three capacity levels (128GB, 256GB, 512GB) but varies its write speeds depending on the size of the drive. The 512GB model supports 500MB/s writes, but the 128GB and 256GB models could only handle 150MB/s and 330MB/s, respectively.
For users looking for a more budget option, the BX100 offers a slight step up in performance from the MX100 while lowering the price a bit. The BX100 will be available in four models: 120GB ($70), 250GB ($110), 500GB ($200) and 1TB ($400). All four are capable of 535MB/s sequential read speeds while, like the MX100, write speeds decrease at lower capacity. The 500GB and 1TB models can handle 450MB/s writes, while the 120GB and 250GB clock in at 185MB/s and 370MB/s, respectively.
In other words, the new MX200 is a tad more expensive than its predecessor ($250 for the 500GB MX200 vs ~$210 for the 512GB MX100), the improved write speeds more than make up for the difference. Meanwhile, the BX100 is everything we love about the MX100 but slightly better and cheaper.