What makes you come back to an AI tool?

I've been building Nuvix, and one question keeps coming up as I improve the product:

What makes you return to an AI tool after trying it once?

Is it:

A unique feature?

Speed and simplicity?

Better results?

Great UI/UX?

Something else?

I'm trying to understand what creates long-term value instead of simply adding more features.

I'd love to hear your thoughts. Your experiences will help shape the future of Nuvix.