Multiple Step-Down Voltage Rails from a single DC Power Supply
The triple converter gets you some space savings while maintaining the basic simplicity of buck regulators.  However, the chip now is a single point of failure.  Multiple outputs from one switching stage will save more space.  However, the magnetics no longer are simple inductors so the added design and development time might eat up or exceed the BOM savings.  Unless you're talking about high volume, I'd go with a triple controller.  I prefer Linear Tech, but TI should be fine.