Hi there, in regards to range issues the RF settings within Instant ON are not configurable, but rather automatically determined by ARM (adaptive radio management). With that being said the AP11s are our lowest end access points (2x2) and models like the AP12 (3x3) and AP15 (4x4) would likely see an improvement. Also, please keep in mind a lot of coverage/connectivity issues also comes down to the client(s) attempting to communicate back to the APs as the radios built into smart phones as an example are only so powerful.
Thank you