All balisongs have at least a slight play in the handles, this helps the motion of the knife. But high quality bali's, like benchmade and microtech, have NO play in lock-up. These companies actually build these knives for use. A balisong is a very strong mechanism. You would have to break the handles, pivots or pins to fail. Some other mechanisms can fail just by dirt being in them. Many people consider the balisong to be like a fixed blade in the open position, but you must rememeber HIGH QUALITY, and high quality is not cheap.
Also make sure to check your local laws about balisongs, due to Hollywood using the knife in every gang movie it had motivated them to be illegal in many places. Yes, a high quality balisong is tough, but expensive also. If you manage to break one of the quality ones, you need to only carry fixed blades... Nothing else will work for you