I recently aqquired a Echo PB46LN blower which had a 65db noise rating. The machine was very heavy, around 25 lbs. Since I wear hearing protection and we have no max noise regs here I removed all of the sound deadening from the machine. It is now under 20lbs.
If you want a quiet blower, go with Solo's new model Model 470 . The Solo company invented the backpack blower back way when, but shindiawa, redmax, sthil are better known products. The Solo does have some quite impressive numbers for a quiet blower.
As toddman35 was saying or asking, when you go to quiet models, you do sacrafice some power. The technology however is catching up.
In my area that I work, more cities are either making new ordinances about how much noise your machine can make or banning them outright. If noise is an issue in your area, i would compromise and go with the quiet models. I can tell you that I will never go back to the most powerful models unless their noise level is at the 62db that my toro is.