It's a good hold set but the reason I stay away from it is because the lack of damage you bring with it. Unless your team is really strong and just needs to hold to skip gimmicks I wouldn't go for it but DoD instead. You can just time your holds at crucial moments and still do damage this way. However, if the 2 or 3 seconds extra duration from the hold actually makes a difference for your team I would say go for it. Assuming you plan to take Necro all the way I would begin with DoD but if you are just using her as a hold slave for GG Raid Pots then I can see why you would go it.