Right, but they're mostly bugs in optional features like 802.11w and DFS. In my mind, there isn't really much of a practical distinction between a missing feature and a feature that doesn't work. The interoperability bugs are perhaps the most nefarious, but don't really impact most people. For my home wifi setup, they've been pretty decent. Their range and throughput are good. I've reliably streamed games over wifi with them. Their CPUs are also relatively powerful, making them good routers. They can be had on eBay for $30-$40.
Buying $30-$40 access points on eBay is a bit of a hobby of mine. I've been using a Netgear R8000 as an access point for a few months. There's no OpenWRT support, but it's supported by FreshTomato. Qualitatively, it seems to work well in terms of latency and throughput when the signal is strong. It seems to perform worse than the WRT1200AC that I was previously using at that location, when at the fringe. When I'm at the center of my house, my phone tends to associate with it but then struggle to get packets through. Maybe I just need to dial down the AP's TX power, though.