Considering the varying body types and riding styles of mountain bikers, is there a universally accepted ideal saddle angle for long rides, or should it be determined on a more individual basis by taking into account factors such as hip and knee alignment, as well as the type of terrain being ridden? Additionally, how much of a difference can a slightly tilted or perfectly level saddle truly make in terms of comfort and performance over extended periods of time? Are there any studies or data that support the idea that a specific saddle angle is more beneficial for long rides, or is this largely a matter of personal preference?