I tried this today and I wished I had read the review first. The same as Judy, my tomatoes were too small and the whites spilled over and the preparation was a little messy. I ended up steaming them on top of little ceramic dishes to catch any overflow. But its worth doing again, it was a healthy and yummy start to the day. I used boiling water from the kettle to speed things up a bit (reduced the recipe by 5 min) and also cut the little rounded bit from the bottom of the tomato bases so they would sit firmly without rolling.
I wouldn't mind doing a larger version by adding some other goodies like mushrooms and baby spinach, or even some ham for a complete meal.