The Samsung 9100 Pro 1TB wins in 4 out of 7 comparable specs, with 2 ties. Its biggest advantage is Sequential Write (217% better).
UD90 1TB wins in 1 spec (MSRP: 72% better).
Recommendation
Choose 9100 Pro 1TB if you want the best overall performance — especially sequential write.
Choose UD90 1TB if msrp matters more to you.