Currently Being ModeratedMar 13, 2013 9:20 AM (in response to AceNeerav)
Apple hasn't published a radiation pattern for any of its AirPort routers, but it is believed that the pattern is somewhat similar in all of them with exceptions due to different antenna designs employed (between models and generations of the same model). With that said, the overall pattern shape is roughly an onmidirectional spheriod with a slight flattening at the poles.
As far as range, a 2.4 GHz network should always provide greater range than the higher 5 GHz band. In practice, you can expect decent bandwidth performance out to 100-150' on the 2.4 GHz band; 50' on the 5 GHz band.