Well, I've got a BB-6500 Octalink bottom bracket that's got over 36,500 miles on it and it's still smooth as glass and free of play, a BB-5500 Octalink with 6,000 miles that's like new and a Shimano BB-UN52 square taper with about 10,000 miles used exclusively on rain/errand bikes and always wet but still in fine shape. So, not all of Shimano's sealed bb's are a POS.