Steve,
I had Tomo, but not for the larynx, so I can't say what difference that might make.

Tomo has been around since 2004 and a lot of the advantages it had are now commonly available with Varian's RapidArc (SmartArc, or Smartbeam) and Siemens VMAT.

Although quite a few independent studies have found Tomo's Helical Arc is still as good as it gets for H&N.

In my case I was sent to the Tomo Center do to concern I would need more areas radiated since I had an unknown primary location with two small nodes that didn't adequately correlate to single primary location.

So far I can't complain - best of luck