I can confirm what @Wallbanger says
Cudy wr1300 is working fine with the last rc3 or latest snapshot.
First mandatory flash with the OpenWRT version proposed by Cudy is a bit annoying (no wan, no lan if I remember well), but after that it is easy to have OpenWRT working on it (you can then install actual RC3 as it includes Lucy GUI, much easier for starters than starting with a snapshot)
You can download this openwrt package on the Cudy's website including all that is needed to unbrick your rooter (very easy, great job Cudy even if your "dev" firmware is unusable !)
In term of wifi speed it appears to be average (300~500Mbps) with a decent 2x2 Wi-fi card in the client on recent OpenWRT builds.
In order to compare, the Archer C80 AC1900 ( MediaTek TP1900 soc 2x 1.2Ghz ... that will never be supported on OpenWRT [4/64MB]) is really faster, with ~700Mbps
OpenWRT support for the wr1300 should last for a long time because its cpu+wifi combo (MT7621A + MT7612E) is very common and seems to don't have a lot of problems actually (eg. no problem with vlans) and has support for HW offloading (seems broken in the actual snapshots but worked fine in 19.07 and will probably work again soon)
and CPU+WLAN driver will still evolve in the futur
It also has an USB 3.0 port, I didn't use it for storage so I can't share any number, but at least it is very usefull acting as an USB power supply for small things near the router (I use it to power a Zigbee IoT gateway, no pb), less mess in the cables
As a low cost AP it is great choice at this price point
As a router its MT7621A cpu is not fast enough if your WAN speed is more than ~200Mbps AND you want to use QOS (SQM) or any CPU related things (like VPN)
without QOS you can expect to be good for a ~500Mbps line speed or even a bit more when hw offloading will work again