I dunno about rock solid. I’ve had plenty of issues forcing a failover/reboot, multiple complicated tickets open a year, etc. But we have a sh ton of them. To be fair, some are kernel bugs with connection table leaks, SNAT + UDP, etc.
Buuuut, they have by far the best support. They’re as responsive as Cisco, but every product isn’t a completely different thing, team, etc. And they work really well in a big company used to having Network Engineering as a silo. I’d only use them as physical hardware, though. As a virtual appliance, they’re too resource hungry.
Nginx or HA-Proxy are technically great for anything reasonable and when fronting a small set of applications. I prefer nginx because the config is easier to read for someone coming in behind me. But they take a modern IT structure to support because “Developers” don’t get them and “Network Engineers” don’t have a CLI.
For VMWare, NSX-V HA-Proxy and NSX-T nginx config are like someone read the HOWTO and never got into production ready deployments. They’re poorly tuned and failure recovery is sloooow. AVI looked so promising, but development slowed down and seemed to lose direction post acquisition. And that was before Broadcom. Sigh.