I have a Netgear router that is an absolute rockstar.
The original firmware was slow and horribly buggy, but I quickly re-flashed it with https://www.OpenWrt.org
Which isn't to say OpenWRT never screws up, but its #FOSS and straight-up #linux so I can always fix a broken service myself, or use an alternative package.
Proprietary firmware you're just SOL without an enterprise grade support contract...