Is it perfect? No, of course not. nothing in this game is invulnerable. There is always a counter to every tactic and/or unit.
But getting a 2+ cover save and still able to pump out 6-20 S7 *hits* a turn is nothing to laugh at. At all.
Add in the fact that while the lootas are behind their wall of awesome, there is a unit of Nob bikers in your face gives them at least a turn or two of worry-free shooting.
At 1750 I lack any allies, which means to psychic defense. Can't have everything!
I'll keep trying this combo out, and I'm sure I'll get up a couple videos on Ork-ifying the Aegis.
Orks vs Necrons: