Zalos Belt or Omega Belt?

I’m trying to understand what to buy in future since I’m fasting levelling up and I wanted to buy Omega Belt till today but I saw that Zalos one is good too.

Zalos’ one buff Sonic Explosion while Omega’s one buff Firestorm.

What is better?

At my level I use both of them, but I’m watching many videos lately to learn thing about this game and I don’t really see very often people using Firestorm so I was thinking maybe Zalos’s one is better for Sonic Explosion.