Joel, all I can tell you is that I've been very happy w/ my KB aluminum hemi block. Been running it since 2006. Ball honed it a couple of times during freshen ups and it ran great every time. Didn't put "fresh" bores in it until 2019 when I hurt 3 pistons due to a nitrous mishap.
Comparing to some other similar combos, I don't think mine is really missing any power.
I think the weight loss is worth whatever small amount of power is lost from ring seal. If you don't need the extra weight up front, I'd go aluminum. Unless you completely destroy it, it can be easily repaired.
Now, I think my car could benefit from an iron block simply for the weight up front to help keep the front down.