I've read somewhere that there is not difference between corn sugar and table sugar when it comes to priming, it's all completely fermentable. i wish I'd read that before I went and bought a bag of corn sugar for $6.
Also, I started to save wort to prime with because I'd read that malt extract results in smaller carbonation bubbles and I didn't want to shell out another $6 for priming sugar. Then I read that all carbonation bubbles get smaller over time. I wish I'd just used table sugar for all my brews. When I use up the corn sugar, I'm going to use table sugar.
However, I'm a newbie. This is just what I've read. I've only ever used corn sugar and wort to prime. I've noticed no difference between those two.