Unfortunately I have to many devices. Especially I can't find a really proper device. In former days the WR841 was a really good and supported device and I still continue with soldering an 16 MB flash and 64 MB RAM into these kind of devices and push a breed bootloader into the device via HEXeditor. I still continue this idealistic work because I haven't found any proper working 5GHz device in Openwrt which is nessesary for me, because I easily need static routes and wireguard support! - This is still a mess just to add a static route in an OEM-FW of any vendor.
So I have WR841v8 and v9, WR740, MR3220, WA701, WA730RE v2 (with 16MB flash and running MR3220-Lede Firmware of pulpstone.pw). These are my 432-devices
Newer devices are Newifi Mini alias Lenovo Y1, Archer C20i and Archer C2 with MT7620A and weak MT76x0e support/signal in 5GHz even with newest drivers and new build firmware.
Xiaomi MI 3 Router MT7620A and also very weak MT76x2e 5GHz wifi even with newest drivers and new build firmware.
So frustrating, testing and wasting time with Openwrt is my favorite spare-time waster...
So, please don't tell me buy an Archer C7 and you're happy when there is no other solution. I am sure even with Archer C7 I won't reach a very good 5 GHz wifi performance.
Actually I was thinking about buying a newer device like Archer AC2600. There should be a support for openwrt already and it has at least a proper new Atheros chipset and not the old dog like Archer C7.
So beside new devices it would be more charming to get rid of the baby-bugs in the code for nearly every older devices. It's really annoying that always the wifi support sucks in openwrt. Even if you try to prevent the NAT by using just the switch and wifi and kick WAN. There is no performance diffrence. - Most devices are stuck around 30 Mbit/s througput via wifi. If it's a lucky day you can reach maybe 50 Mbit/s, but that's it independen of 2,4GHz or 5GHz. - I have no busy neighbourhood and I am always testing beside the devices with distances under 3m in the same room....