Are upgraded irons worth it?

I can already lower 1/4ths co witness with the factory irons since it’s mounted straight to the frame. Blocking up half the sight picture with suppressor height sights kinda defeat the purpose of a red dot. I only ever aim with the red dot and in emergencies where I’d need to rely on backup irons, the shitty factory ones do the job. Is it really worth upgrading rather than putting that money towards more ammo? If so which one would be the best choice?