I used to use their Citrix Netscaler VPX1000s at a previous job.
They were very reliable, imo. Aside from general Netscaler bullshit, We only ever had issues with them when we'd try to get them to do too much so that the CPU or Memory was overloaded.
We tried on a few occasions to get more cores allocated to them, but no. This made terminating large numbers of SSL connections on them problematic.
I was using their shared loadbalancers, not the run a load balancer in a VM option, because I was hoping for something more reliable than a single computer. For the couple months they were running, it was literally every 30 days, 10 minutes of downtime. So I went back to DNS round robin, cause it was better.
They were very reliable, imo. Aside from general Netscaler bullshit, We only ever had issues with them when we'd try to get them to do too much so that the CPU or Memory was overloaded.
We tried on a few occasions to get more cores allocated to them, but no. This made terminating large numbers of SSL connections on them problematic.