The Samsung 9100 Pro 8TB wins in 4 out of 7 comparable specs, with 2 ties. Its biggest advantage is Capacity (300% better).
NM1090 Pro 2TB wins in 1 spec (MSRP: 69% better).
Recommendation
Choose 9100 Pro 8TB if you want the best overall performance — especially capacity.
Choose NM1090 Pro 2TB if msrp matters more to you.