Unfortunately, the antenna on the RPi is not great, due to it being a PCB-etched pattern antenna.
For client, the range seems really good, thought not nearly as good as something like a cell phone, probably by about half.
For AP mode, the uplink speeds from the device connected to the RPi seems to be almost completely uninhibited, while downlink is pretty bad. This is where the poor antenna comes into play, since the RPi can't broadcast its SSID very strongly, and really only works well within LOS of the device. From another room, download rates drop pretty low, to sub-5Mb.
It may not work very well for transmitting video or something, but it's certainly good enough for low-bandwidth applications.
For client, the range seems really good, thought not nearly as good as something like a cell phone, probably by about half.
For AP mode, the uplink speeds from the device connected to the RPi seems to be almost completely uninhibited, while downlink is pretty bad. This is where the poor antenna comes into play, since the RPi can't broadcast its SSID very strongly, and really only works well within LOS of the device. From another room, download rates drop pretty low, to sub-5Mb.
It may not work very well for transmitting video or something, but it's certainly good enough for low-bandwidth applications.