RE: Is it smart to fly with Hitec servors in My bigbird?
Although I prefer another brand, the failure rate of any type of servo depends largely on the care expended during the installation. A poorly installed "gang" due to linkage binding and over loading can, and will, cause any product to fail. An installation well thought out and checked to locate and eliminate issues will have a much longer lifespan and proportionally greater performance levels. Whenever multiple servos are used to drive a single surface, faster part wear should be anticipated and more frequent checks made to verify the servo(s) condition.
Other that the above, any product that's man made has a potential for failure, and we as users have to take the time to assure that each unit is working properly prior to the first flight. And each flight thereafter. Basically, chose a product that suits your needs and exercise the care necessary to assure success.
Pat