You need to pull timing, it WILL NOT be sluggish, always remember that N2o is not flamable, its just "oxygen" in a bottle, think of it as changing Altitudes from say 5000ft. too sea level, there is alot more "air molecules" at the lower Alt., you then need "less" timing & more fuel, this is basically how Nitrous works, but to much higher extreams, i play it safe anymore, i'll list the bare minimums that i run to be safe, N2o can be fun, but it will add up.
Bare safety:
Bottle heater/warmer (you NEED to maintane a propper bottle pressure to benefit)
Window switch: This allows the control of when you want the nitrous to come "on & off" in any given RPM, this is a cool device to have.
Bottle pressure gauge: a no brainer.
Dedicated fuel system: Wether its a 100 hit, or 200, it is always a good idea to do this so you can program/maintane propper flow for the plate.
Propper plugs: Its always best to drop at least 1 heat range colder, even on 100/125 shot, along with narrowing up the gap to around .032", now if you go with a higher like 150-200, i'd drop 2 heat ranges.
Propper fuel/octane: As you know, pressures in the cylinder dramadically increase, so it never hurts haveing a higher octane for the N2o.
Rev. limiter:, this is just incase something lets go in the drivetrain, you already have your "window switch" to kick off the nitrous, so it still won't be "spraying" when its on the limiter & of coarse you won't over-rev & spin a bearing.
PULL timing accordingly!!
Play it safe & nitrous "can" be your friend. My 2 cents.