This is the fourth and final 850 Pro single drive review we have to publish. On launch day, we tested the massive 1TB drive, and the surprisingly speedy 128GB model. Last month, we looked at the 512GB drive, which offered a perfect balance of cost, performance, and capacity. Today we’re looking at the 256GB model, a super-fast SSD that costs less than $200, yet still retains the title of “The Most Advanced SSD on the Market Today.”