I think the 2 have the same healing ingridient & again I 'm with Sarah on this I too use normal powder cinnamon in a jar you buy at the supermarket....A jar lasts years!!!!!
Actually, if it's McCormicks, then it's probably probably Cassia bark. (Which is fine, Cassia is tasty, and in things like pumpkin pie, I do a 2:1 of it to the real stuff, it has a stronger flavor than real cinnamon)... (If you are a spice junkie, I HIGHLY recommend penzeys, they are WONDERFUL.
I'll do some poking to try to see, but my guess is that if folks are using the stuff from their cabinets, then the cassia is fine.. YEAH!!!