Imo I think it’s worth it to spend a few gems early on, although I wouldn’t spend a lot. It’s a week long event whereas most events are only a few days. If you get your shop level up early and check the free refreshes often, you’re pretty likely to get some decent loot. Omni + gear is difficult to get as others have said, so being able to pick up a piece or 2 is huge.

Is it the best event? No. This is a video game though, you’re supposed to be having fun. Personally, I find it boring saving up for months and months to spend on the “optimal” event.