I played in an apoc in my games workshop the other day, and it was necrons (and one BA player) against orks and one tyranid and one daemon player) (necrons and BA vs tyranids, where have I seen this before) and I hink thatnecrons are incredibly OP in apoc.
orks had all the advantages, they had 2 stompas (one goff rolla, one big mek), a squiggoth, a sythed hirodule, a fighter bomber along with the rest of the army and first turn.
the necron army was 20 scarabs, 1-2 monoliths, 20-40 warriors, 15 lychguard, orikan+2 c'tan, one with WW and a collection of lords and crypteks the necrons also had somthing called a resurection warcell but I'll get to that later

the first turn had orks bomard necrons with stompa 7" templates and giga shootas.
they kill some lords, 10 scarabs and mostof the warcell. then the warcell shows it's first power, a 2+WBB. then on the necron turn the scarabs eat one stompa and the warcell summons more scarabs ankyr gets the mek stompa to fire into boyz, destroying a large chunk of them

ork tun, tyranids and fighta bomba strafe and deepstrike into the necron lines and army generally shoots, moves and some minor assaults necron turn uneventful exept a monolith deepstrikingand bringing 10 lychguard bhind the orks

ork turn ghazkull attacks lychguard. by he end of hegame, him and his nodz will actually lose this combat! tyranids assault warcell with genestealers necron turn, warcell summons monolith which portals a trygon!!! ankyrstill using stompa to destroy its own army

ork turn, genestealers LOSE to 30 warriors part of warcell) and ork assault is starting to get a few holes. necron turn. 3 scarabs assault the 1000p mek stompa and kill it!, destroyers kill fighter bomba and monolith portals DoM when its at S 10! orks call it as they have almost nothing left (I cant remember what killed the squiggoth/hirodule, but they did die!)

(=I think this is OP)

from this I found that scarabs are monsters in apoc and that warcell is extremley OP

was this a one off or have you had other experiences with necrons being this OP in apoc?