hi9's were actually designed for daily driven rigs. We run them in our comp crawler and never have any issues. In a 609 front application there is not a stronger unit out there unless your go to gearworks for their 10" stuff. In a rear they are not as strong as a low pinion 9 but still stronger than a stock 9" and if your building a complete center section with all aftermarket parts they are not hugely more expensive, only about 10% more. In a rear they are great unless you have lots of power and drive like a ham fisted, knuckle draggin neanderthal, then you really need to look at stronger options like a Dana 80 or 14 bolt.