I haven't tried the Edge, but C2 isn't very good. They took out the all the sugar instead of the high fructose corn syrup, which changed the flavor, and added back in both aspartame and Splenda, but mainly aspartame. I can definitely still taste the aspartame, and I can tell that the drink lacks real sugar. If Pepsi Edge tastes anything like C2, its gonna suck.
My solution for cutting out soda (and the related calories) was to simply give it up. I have maybe 1 soda a week, at most.
R