I would choose Reborns over DX simply because Reborns is what a paper should be. Long range weapons, missiles, funnels, and range SP.
I prefer Sinanju over NT-D because of the stun. People say it is a difficult MS to use, but it is not that hard once you get familiar with the timing. Plus it becomes a good melee MS when you purge, not to mention that Bazooka that can kill mobile armors in a flash.
NT-D isn't bad, but when you can't melee with the slow ass animation and you're forced to just spam the magnum, then it becomes a one trick pony for me. It repels funnels, big whoop. Sinanju can poke with the stun gun, the tomahawks, and then SP when the enemy is soft enough. Switching between range and melee mode is crucial as you cannot revert back. It becomes holywtfbbqfast when Ghost of the Red Comet kicks in.
"You are already dead."
00 Raiser, 00 7S/G, V2AB, Infinite Justice, HWS v, Master Fuunsaiki, God Fuunsaiki, SR Sazabi, Crossbone X1 Kai, Stargazer, Crossbone X3, Sazabi
Upcoming projects: Arios Ascalon (100% Complete!), Crossbone X1 Skullheart (100% Complete!)