For me, learning bike mechanics has been a definite positive in my enjoyment of bicycling. I much appreciate not having to go the LBS route for most things. There are 2 really good bike shops within 12 miles of my house, one only 3 miles, and I do still use them when I feel I need it. As for the mechanics, I really think they appreciate a bike owner that keeps up on the maintenance and has knowledge of the mechanics.