Does anyone know the actual amount of magic acc these give? I've read that elemental staves give 20 or 30(HQ) to the corresponding element, but Iridal/Chat give 10 and 30 with some sources saying that Iridal actually gives 20. I feel like my luck is better with the corresponding elemental staff, but it's hard to say for sure and I'd like to hear about your experience.

I believe iridal is supposed to have the same macc bonus as the other nq staves and that the ffxiclopedia entry is in error (BG shows it as 20 instead). It was made to be the equivalent and the HQ is equivalent to the other HQ staves, it would make no sense for iridal to have less macc. Having said that, I do not know how it is implemented here on nasomi. Many of these things are implemented based on community sources, so if the stats on it were pulled from xiclopedia its possible that it is 10 macc here (and therefore incorrect).

I'm pretty sure its just magical affinity +1, which bundles magic acc, magic damage and -avatar perpetuation in one. Yes it's possible that they followed the incorrect ffxiclopedia data, but I highly doubt it, as pages like this https://www.bg-wiki.com/bg/Iridal_Staff give the correct statistics on it.

Also, Iridal/Chato have extra INT, and Iridescence which means they'll always be better than their elemental alternative. (Except aquillo's)