Nightshields worth it?

10 points a piece. -6" range on weapons shooting at the vehicle with nightshields. In my venom spam list I'm dedicating around 100-120pts to get night shields on every vehicle. I realize AA weapons that are going to be shooting at my vehicles most of the time already have range even with the -6", but I find avoiding small arms fire almost always pays for itself. What do you guys think? Are nightshields worth it or just a crutch to avoid bad movement?

I'd say it would be worth it. I mean the small arms fire from bolter equivalent weapons will kill just about any skimmer though mass glances in this edition through all the armies. Not to mention the necron weapons glancing stuff to death in this edition.