Barry,
treatment planning for IMRT is usually always done with a 3D CT. Sometimes they will also use fusion with a CT and a PET scan. I seriously doubt that what you described is a "further development", but rather some marketing spin on the tried and true.

When got my treatment 2 years ago, most regional treatment centers were just getting the LINAC upgrades. My RO is the top IMRT doc in the US according to the Castle Top US Docs book. She had a lot tricks up her sleeve (like limiting the dose through the thyroid and irradiating many lymph areas and the left tonsil as well) which she used based on vast amounts of experience and huge patient volume. She's also a clinical professor of radation oncology.

One of the things you want to ask in choosing a treatment center is their mortality ratio.

Although IMRT has been around for over 10 years now it was initially developed for prostate cancer. So the H&N application didn't start until some years later.

The cyberknife is used mainly for inoperable brain tumors. They have one at UCSF as well.