So far, Sabrent has only detailed the 2TB version of the Rocket Q M.2 2230 SSD, which is based on Micron N48R NAND and Phison E21 controller. It peaks at 5,000 MB/s and 3,200 MB/s for sequential read and write performance with random 4K read and write at 480K and 750K IOPS. The 1TB version details are yet to be announced.
With such specifications, the 2TB Rocket Q should be significantly faster than the stock SSD that comes with the Steam Deck.
As said, the Rocket Q 2230 2TB is available for pre-order directly from Sabrent at $219.99.