Been using Openwrt for years, router and access points. Any new AP I buy has to has to be supported by Openwrt. I have probably bought 7 or 8 old AP's at yard sales over the years for $5/$10 and turned them into decent wifi access points back to an Openwrt router running vlans, bandwidth monitoring, QoS, tcpdump for ssh dump with wireshark.

Just excellent, some pretty smart people in the Openwrt forum as well if you have problems.