There is so much Nyzul gear out there that it's almost certain that a good portion of it has been acquired legit. I want to make a few points:
-Kill speed is so important, it just cannot be understated. You cannot bring sub-optimal jobs and expect to win regularly.
-With that in mind, for a raid that offers such incredible rewards, it's probably entirely worth your time to level and gear an optimal job for it. SCH is not hard to gear (it's difficult to reach 500 enhancing, but getting it to a point where you can cap magical haste with Haste spell is easy). SAM is easy to gear. A good BLU is so invaluable it's ridiculous, but requires a lot more effort.
-Increasing your movement speed via hacks will give you a very high win rate, but will very likely get you suspended. However, this should give you a good idea of how important powder boots are to a successful run. Yeah they may be 80k each but you should carry enough to full time them and always have one ready to go (ditch your normal feet gear and full time powder boots).
-Skype or some type of voice chat is essentially mandatory. You can't easily type and run.
-Communicate. Have an idea of how you are going to split up on floors. You lose precious seconds when somebody doesn't says "I'm at lamp, should I hit it? Should I hit? I'm gonna hit it... Hit!" Have an idea of who is stopping to clear this room, who is going to keep running. Do you need to team up on this nm? Is it that ****** pudding that needs to be skillchained? Is it that ******* flayer that uses unbridled learning? Is that Byakko? Might wanna take it first and switch targets when he uses PD.
-Even with Embrava and Regen you can still die. A lot of people forget this.
-Lamp dats are a sticky issue for me. They are extremely useful and can easily be the difference between winning and losing. As far as I know they are essentially undetectable, particularly if you keep all your chat on skype. I personally think it's cheating, but you're not going to get caught for it.
-Other small tips include having accession up for the next floor, casting sneak immediately upon zoning up, using powder boots for specified enemy/enemies, leader, and lamp floors, using body boost at start and middle of the run, everybody having sprinters/clerics, everybody should have a ranged attack of some sort for "do not aggro gear" floors.
There's too much gear out there for everybody to be cheaters. Even if you only win one out of every 10-20 times, you are guaranteed to get a piece of gear that is best in slot for multiple jobs. The most important thing is persistence.
Philemon on Valefor