Please see my
battle report for the full thing.
Here's a copy-paste of my suggestions.
To be honest though, I've come to think that more than 2 Pylons are really hard on air-heavy armies. More precisely, I'm concerned by the possibility of the combo 3 Pylons + C'tan, which I'd definitely use for a tournament army. The Abattoir and Orb are nice and fun and I really love them, but no competitive Necron player would go to a tournament without a Supreme Commander and a Strategy Rating of 3 instead of 1... and the possibility to still get 3 AA shots of death with that seems a bit too powerful.
I know the list review is only due in the distant future, but I'd like to propose
a points increase both for the Pylons (+25) and for the C'tan (+50). That way, it wouldn't be possible to take more than 2 Pylons with a Supreme Commander. Also, the C'tan are a bit cheap at only 300 points, particularly the Deceiver and its 6 BP Disrupt attack. 350 points would be on par with the Warbarque.
I'm expressing the concerns of several French players (see the recent discussions after the Lyons' Epic Week-End on the epic_fr forum). I personally believe the Necron army is fun and well-balanced and that it only needs a few tweaks.
So:
Pylons at 225 points.
C'tan at 350 points.What do you think?