The WL-WN523N2 is an device. This means it only operates on the 2.4GHz frequency. No matter how "good" the firmware is, it will never reach the speeds of a modern WiFi 6 (AX) or even a WiFi 5 (AC) router.
Only if you are an advanced user looking for specific features like a built-in VPN. wlwn523n2 firmware better
Unlike some “improved” firmwares that break older clients, wlwn523n2 was validated against: The WL-WN523N2 is an device
To determine which firmware is "better" for you, check your usage: requiring a hardware programmer to fix.
: Attempting to install the wrong firmware version can permanently damage (brick) the device. One user noted their unit became unusable after installing incorrect firmware, requiring a hardware programmer to fix.