OK, I'll be the dissenting opinion here...
I have a GE Spectra glass-top stove, and I LOVE it. I would never go back to gas. It's about 10 years old, and when I built a new house last year, I insisted on moving this old stove with me. I plan on using the oven door as my tombstone--the closest I can get to taking it with me.
I have found that using heavy pans and a low setting help to keep the heat at an even level. I have some old Calphalon hard-anodized pans that weigh a ton, and also enameled cast iron, and I never burn things with these (except if I just do something stupid). I've been less happy with stainless steel, and you can forget about cheap pans.
I do think there is a huge difference across brands of glass-top stoves. I bought a Kenmore for our cabin last year (very limited choices for a 24" stove), and it's really difficult to keep the heat at a consistent level with either the glass-top or oven.