Hard to say - both are chance based and can give you some extra time, which can save you in a tough run. With the current average unlocking cost (details) I don’t recommend trying to get either of them, but if you can afford it, here are some things to consider in your decision:
Factors that make Camo Cloak more attractive than Shield Generator
- Have already unlocked (or intend to get) Plaster and/or Metal Detector, or don’t have Premium gear but have Iron Sights at a higher level than Explosive Bullets
- Main (or intend to main) heroes with Shield skill tree (the more Shield you get from the skill tree, the less impactful is the shield from the Generator)
- Have Iron Sights at a higher level than Explosive Bullets
- In Dark Castle / Endless / Endless Boss you tend to take Safety Bubble as a perk so that you have a chance at Shield Ward (from what I’ve noticed, if you have the Safety Bubble, the Shield Generator does not activate)
Factors that make Shield Generator more attractive than Camo Cloak
- Already have a lot of attack bonuses (Level 20/50) against Ground enemies (there are no all-hero level bonuses for Ranged enemies)
- Have already unlocked (or intend to get) Sim Chip, or don’t have premium gear but have Explosive Bullets at a higher level than Iron Sights
- Want to do better at Endless Waves - Camo Cloak is useless (all enemies are flying, and the cloak can only proc at the start of the run) and if the Shield Generator procs you essentially have Safety Bubble in the run for free
- Want to do better at Thursday Fire event and/or Fire castle - all mobs are flying so the only time the Camo Cloak boosts damage is in some boss rooms.
- Main (or intend to main) heroes with Decoy Skill Tree (if the Decoy deploys when the Cloak is active, enemies start shooting at it and you can get hit even if you are invisible, especially because the decoy sometimes ends up running around you
)