I've had a 13" iBook G4 (white plastic) and a 15" powerbook G4 (aluminum). The WIFI reception on the iBook was great; the powerbook NOT so good. Probably the aluminum interfered with reception. Others share the same issue, so it was not just my particular machine.
Anyone know what the WIFI reception is like on the new 15" (aluminum) macbook pro vs 13"(plastic) mackbook?