Just thought id add my input in on the new necrons.
The scarabs are immense considering the cost, they are no longer jetbikes but beasts giving them an effective 24" charge range if lucky, they are perfect for taking out high av vehciles, or any vehciles for that matter. Put 30 swarms in a list and thats 150 attacks, for every hit they get on a vehcile you roll a D6 and on a 4+ it loses a point of armor on all sides, then after that they get a strength 3 attack on that armor, i took 17 swarms against a mechanised guard army, i tihnk they killed 4 chimeras and 2 basilisks.
The destroyer lord is also very good, Give him the 2+ armor and you have a T6 2+ armor save, s7 monstrous creature basically.
The destroyers however are no where near as good in my eyes, they are good for MEQ armies but other than that there is no point, 2 shots at str 5 AP3, rather than 3 at Str 6 AP4, they arent good for popping transports at all or taking out latge chunks of troops either.
Havent really checked out many other of the new units yet to be honest.