I tested vSphere 6 quite intensively when it was in beta, but I didn’t ever upgrade my lab - basically because I need a stable environment to work on and I wasn’t sure that I could maintain that with the beta.
Now 6 has been GA a while and I have a little bit of time, I have begun the lab upgrade process. You can see a bit more about my lab hardware over on my lab page.
Recently I installed and configured a client’s new ESXi host, they’re a small company and only require a single host. The host in question was an IBM x3650 M3, an excellent workhorse for virtualisation and one of 5 or 6 of the same model that I’ve installed in the last year. In addition to the onboard Broadcom Dual Gigabit NIC, we always install at least a second Intel PCIx Dual Gigabit card for resilience/redundancy/performance.