The 3.0L engine is pretty bulletproof
I would say that the N52 stands low in the spectrum of bulletproof by modern standard. Ignition problems (I had issues with 3 cylinders), leak problems (just cost me 1K$) to fix, exhaust valves were changed and I always dread the famous water pump problems (again relatively expensive).
I miss my M54 and its little coolant problems. lol.