Good for high bar squatting and other quad-centric leg exercises.
Almost a necessity if you have poor ankle mobility. Obviously you're gonna wanna address that, but in the mean time oly shoes will give you optimal positioning.
Got the older Adistar oly shoes. I love 'em. Had em gifted to me, tho. Wouldn't pay $200. There are cheaper alternatives with similar wood/plastic heels. If you're going oly shoes, stay away from cushioned heels. And like breh said, these need to fit like a glove. Read reviews to get a feel of sizes (do they run to big/small, narrow/wide, etc).