Planet WNAP-7300 (Zcomax ZCN-1523H-5) with OpenWrt r29664
It turned out to be just like I suspected , Planet WNAP-7300 (at least with firmware "2.0.3(PL)4") is exactly same device as Zcomax ZCN-1523H-5. Atheros AR7240 rev. 2 at 350MHz, Atheros AR9280 rev 2 5GHz radio, 32MB RAM, 8MB Flash and two 10/100 Ethernet ports. Therefore it works with Zcomax OpenWrt firmware. Bridge performance seems acceptable, around 70Mbit/s real world in bridged mode and 60Mbit/s if OpenWrt is doing NAT. With around 25 meters nearly line-of-sight performance is ~40Mbit/s. All tests uni-directional TCP (FTP/HTTP) with no other traffic than ICMP echo going on at the same time.