The most advanced releases of iOS -- 4.0.1 and the 4.1 beta -- do indeed have better reporting of iPhone signal strength, tests are said to show. Anandtech notes that the dynamic range in the new firmware is better, and that the range assigned to each signal bar is generally wider. The main exception to this is the fifth bar, which in the v4.0 firmware occupied a disproportionate amount of the scale.
