Headgear does not prevent concussions well. You still need to keep your hands up. You can get knocked out while wearing headgear.

Boxing headgear does protect from cuts, scrapes, reduces swelling and prevents skin damage. Headgear also does a great job of preventing cauliflower ear. Headguards with cheek protection, protect a larger area.

Leather headgear generally lasts longer and looks better for longer than vinyl, but the modern vinyl headgear are pretty decent.