I would go with Shimano! I have had a 180mm XT hollowtech II crankset on my single speed mountain bike for a couple years, I've neglected it and have been quite hard on it, yet it still spins as freely and reliably as day one!! It's sealed very well and has been the most trouble free crankset I've ever used. Just sold my SS and the only thing I kept was the XT, I just put it on my cargo bike as it is so realiable and trouble free.