A few things. First, IANAMD, but I do work in a cardiology clinic doing nuclear heart scans and have been in the radiology field for almost 10 years.
Electron Beam Tomography is basically the same thing as CT or, computed tomography. You are still being bombarded with x-rays to form an image. The difference here is that the beam is highly collimated, meaning a smaller area of the body is being exposed and, therefore, less exposure. Also, in conventional CT, the cathode rotates around the gantry with a wide beam of x-rays hitting the other side, where the detector sits. EBT uses an array of tungsten rings to generate a fan beam of x-rays for scanning, along with a complementing array of detectors. Both technologies use an electron beam focused at a tungsten target to produce the x-rays. (I laughed when I heard the term EBT. Sounds like they were trying to make it sound pretty spiffy. ;)) The advantage of EBT is that you can do the scan with a significantly lower dose, due to the good collimation and the simultaneous redirection of the x-ray fanbeam. A big problem with heart scanning is that you’re trying to snap a picture of something that’s moving at usually around 60-100 beats per minute. Your exposure has to be very quick to catch it clearly and this is another area where EBT is better than CT. EBT can take a very quick exposure which can measure calcium in the coronary arteries. Most plaque in the major vessels supplying blood to the heart contains some calcium, so if calcification of the arteries is seen, that strongly suggests coronary artery disease(CAD).What they fail to mention on that site is that EBT does not give true 3D reconstruction due to its nature (would take a while to explain), so it relies on an itterative or (guessing) software to create the most accurate 3D reconstruction. In its defense, though, itterative processing is widely used in radiology.
Now, as to the ethics of advertising and suggesting this to everyone. Well, that could be a great debate, including all the drug advertising, but here are some facts:
We’re finding out that the sooner we catch CAD, the better we can control it and prevent heart attacks. With the new materials and technology available, cardiac catheterization and stenting procedure are saving more and more people every day.
The accuracy of this test hasn’t really been seen over a long time. It is a relatively new technology. My experience has been that many of the patients referred to me after having an EBT heartscan have had positive nuclear tests and, consequently, positive angiograms. Many of these patients have been helped by medication, angioplasty, stenting or even bypass sometimes, depending on the need.
Radiation is a tricky game. Frankly, no one would worry about having the test if radiation exposure weren’t involved, right? Almost ALL regular, diagnostic radiology procedures have quite low doses. The problem is that 1 or 2% of risk. Of course, the older you get, the less risk you take from these procedures since, as we age we become more radio-resistant. My understanding is that EBT has a significantly lower dose than traditional CT.
My personal feeling is that everyone with a family history of CAD should be seeing a cardiologist for checkups periodically. My experience is that that is the single most common risk factor out there. We haven’t been able to escape our genes yet. 
Here’s an article on CAD risk factors and prevention if anyone is interested.
Conclusion: I think it’s a good idea for people who have some risk factors or especially those who have symptoms of CAD to have some type of test to check for it. There are many out there and this one seems to be an accurate one so far. as always, consult your physician, yada yad ayada… 