If you are trying to improve the existing APs wireless range, it is unlikely changing the device will have a huge impact.
Wireless range is determined largely by the wireless output restrictions set by law. Every AP in my experience goes relatively the same distance. Yes, some are terrible, but as an example my Sky Hub, BT HomeHub 4, BT Homehub 5, Homehub 6, Netgear Nighthawk, Negear D6400 all have very similar range and all struggle in my back room.
The only real fix is to get an additional AP usually and have 2 APs broadcasting the signal.