It was my understanding that the vsphere client would work the same as it used to in previous versions of esxi and only the new features would be exposed in the web client.
I've found the vsphere client to still be sufficient for managing a single host running 5.5. Nonetheless, I rebuild my host and vcenter server vm every 60 days so I can have the web client. I have to remove and re-add the passthrough devices to my vms, but I only have a few that I pass through pci devices to so it's not that hard.