Is the wifi stable? I have a 2017 model and the router will stay up for 7 days but the radio 12 hrs and 3days 2.4 and 5ghz respectively.
Not especially, I had to reboot it occasionally, maybe once per week? In spite of their popularity I never really got on with this router, hence the low price. Some people really rate them though - I guess its the firmware options and the nice WebUI
Having said the above, the TP-Link routers I also tried at the time were similar and needed the occasional reboot, so par for the course, I would say.
If I don't sell it, it'll go on ebay, they sell well on there and typically for a lot more than its listed here!
C