Inbound--- Well, I don't have anything to compare it to but the range seems very good to me. I live equidistant from IAD
....about 30-35 miles from each. From that distance, I can vaguely pick up the pilots responding to the tower. I cannot pickup the control tower voices (this is normal because you can hear the pilot much easier since the plane is in the air and the frequency to your scanner is unobstructed). The tower to your scanner faces many obstacles from that distance. Anyway, the approach/departure frequencies from all 3 airports is easily heard from my house. Planes cruising 37,000 ft over my region have to contact Washington Center and I can hear the pilot's communications easily as well. I would say that to hear the tower conversations clearly you should be 10 miles or closer.
I also live 3 miles from a general aviation airport (no tower) and I can pick up the Unicom frequency perfectly. I've used it while driving and it's great.
Also, I've picked up police/fire from downtown DC which is a good 20 miles from me. For the money, I'd recommend this scanner.