That 30 ring isn't too useful for anybody in shape. I wrote a lot about this recently in other threads....go read them if you are interested in changing the configuration. I was thinking of a 54-45-36. You could also make a 52-44-34 that is probably more reasonable. I still think the 36 ring is perfect for me as a starting point.
One advantage the middle ring has is that you can use any gear on the casseette and not get a lot of chain deflection. With a double, you have to be careful about using the outer gears with the inner ring due to chain deflection.