I enjoy using Smash Balls, but my roommates don't so I usually have them turned off.
People act like Smash Balls are broken, but that's not true. If a Final Smash is a one-hit kill, then it's usually avoidable. The ones that are least avoidable are the ones that're not that powerful, but merely rack up damage or use some other side effect. Then there's Kirby's which falls in the middle; it can either just damage you, or kill you depending on percentage, but it's avoidable if you can get out of its range.
At first all Final Smashes seem completely broken and cheap, but there's more strategy on both the userss and the runners' sides than you'd at first expect. Now the Dragoon, THERE's an item that's completely broken.