The list of improvements is here (according to the Associated Press).
One neat one: the parliament will elect a few representatives for French citizens living abroad. The Democratic Party does that now (Democrats Abroad gets a few delegates -- Barack won them by a big margin). I think the Republican Party does it as well. But, of course, the Congress does not represent American citizens living abroad, except that they can vote in at their last American address.
The French constitution is not as democratic as the United States, and this is a move to democratize the Republic.
So.....if France can improve its constitution, can't Illinois do the same? Vote yes for the constitutional convention.