use the CLI
it's time to follow the lead of AWS. Go CLI and forget the slow, cumbersome UI. Let pissed off users or sufficiently motivated consultancies write Python interfaces to CLI calls. You don't need a dashboard anyway that's Nagios' job. Write wrapper scripts in Perl or Bash. UI and UI portability is a fools' errand.
Or just go back to the old .NET windows-only client. Nobody cares if they have to keep a Winblows box around to admin via VCenter.