Comment 106 for bug 182716

The poor performance of the early BCM4306 units - the ones that use b43legacy - is known to us. Those models have the least work done by the firmware, and the most by the host cpu. The mistakes in the reverse engineering all add up and lead to the result you noted. By the time you get to BCM4306 rev3, then driver b43 is used and the performance is better.

In terms of the hotkey, the key needs to return the keycode 238 (KEY_WLAN) for press and release. I don't know enough about keyboard mapping to figure out how to check for the code emitted from your button, or how to set it up.