Artifact Question

[incognito]

1) Can artifacts change the course of the game (examples welcome)? I have so focused on Posts about rushing for air queen elementals, or getting to alt-3 in a hurry or getting con-6 even, that it never occurred to me to go for con-8 until very late game. In reading artifact descriptions, I think I may have missed an opportunity here, but would like first hand accounts of the difference they make and various strategies to employ them.

2) Specifically, gift of kurgi is cited as feebleminding its owner. How do you combat this effect? Are there other items whose curses/problems outweigh the benefits?

FWIW, I've scanned past threads on the topic but generally find them incomplete.