AData has been lax on the information on this line (just labeling the entire line "up to 3000MB/s"), but it appears true (from pictures of boxes I've seen on reviews). Best I've been able to collect is the max sequential write on the 256GB model is 1200MB/s, 512GB is 2300-2350MB/s, and 1TB is 3000MB/s.
Userbenchmark.com comparison appears to loosely support this.
This keeps it pretty much in-line with the Samsung 970 Pro, which doesn't have a 256GB version, but matches pretty closely on the 512GB version.
Edit: It should also be noted that that reviewer is also getting mixed up, as the 970 EVO 250GB model is advertised with 1500MB/s write, even the 970 EVO 500GB is only 2300MB/s, which is the same on the 970 Pro as well.
And this also falls perfectly in line with the similarly announced HP EX950 line which uses the same controller as this offer, and advertised 2250MB/s write at 512GB, 2900MB/s at 1&2TB (they have no 256GB model).