As more products come to market with three-bit-per-cell NAND, drives like Transcend's SSD370S with MLC become increasingly attractive. Micron, SK hynix and Toshiba all failed to make planar TLC as fast as Samsung's existing V-NAND flash. And so very low-cost drives will continue to enter the market, bringing down the average selling price of all SSDs. However, the quality and user experience will slide alongside them.
Micron hasn't said too much about dialing back the MLC flash sold on the spot market or by contract, but for the last several years, the company has cut back production. At this time, Toshiba's MLC is more expensive than Micron's. SK hynix is finally sharing flash with some companies, and when its new fabs are finished, we'll see more from that company. What we don't know is how the increased emphasis on shipping TLC will affect MLC output. I suspect that third-party companies without NAND manufacturing capabilities, such as Transcend, will have a problem securing MLC for final assembly.
At this point, we can only really recommend grabbing an MLC-based SSD while you can. That's not to say Transcend's SSD370S is the drive to buy, though. Prior to writing this review, I dug into the state of 512GB-class pricing and found that this isn't the best deal at its $176 price point. It's also not the fastest option out there. Samsung's 850 EVO is priced lower, and the SanDisk Extreme Pro was recently discounted to an even lower price than the 850 EVO. Compared to those SSDs, Transcend's 512GB SSD370S just isn't a viable option.
Prices will certainly change over time, and that may be when the SSD370S 512GB emerges as a better value. As MLC slowly phases out, we'll see more TLC-based drives with their own shortcomings. We've already seen this from the BX200, which replaced Crucial's BX100. If Transcend can keep this model around as the competition transitions away, the SSD370S will be worth keeping an eye on.