I purchased a 3B+ to replace my 3B. I plugged in the same micro SD card and booted up. On the plus side I can definitely tell that it is a faster processor. On the negative side the VAP has a range of perhaps 50 feet, line-of-sight only, any house walls and I lose the signal. With my 3B I could relax comfortably in my office 100ft away through several walls. I compared the configuration files:
hostapd_3b.conf:
hw_mode=g
channel=6
hostapd_3bplus.conf:
hw_mode=a
channel=48
Am I reading this correctly? Wireless-G performs better than AC? That doesn't seem right.
My laptop is only two years old. System 76 Unbuntu 16.04.
Longer frequencies in the G band can pass through walls more easily than high frequency AC.
You might want to use a better external WiFi adapter either way.