Gonna rock the boat here. The 3.0 are the better choice for longevity. Parts are way cheaper. The trans typically last longer and over all they have fewer problems. I've worked with both. 3.0i have and will continue to clock the largest original miles(on this board and others) for motor and trans. I would love for the high milers to chime in. I'm at 156k. 4.4i motor and trans have typical issues. try e38.org. same motor, same stuff. Now, power is nice, but general use 3.0i