I've made from scratch/scratch, from marshmallow and bought it.
Scratch/scratch: a bit of work and you have to have glucose. Nice taste. Sugar, shortening plus flavoring.
Marshmallow: super-quick and if you like the taste of marshmallows this is right up your alley.
Bought:
Wilton: The worst tasting. Avoid this if possible.
Pettinice: Okay tasting, rolls nicely. I like this for deep colors, like black, green and red because I don't like adding so much food dye. Plus the color is consistent.
Ingredients: White: Icing sugar, glucose, partially hydrogenated vegetable oil, water, artifical flavor, gum tragacanth, glycerine, cellulose gum, modified starch, potassium sorbate, acetic acid, titanium dioxide, vanilla flavour.
Satin: Good taste, rolls nicely. From our local cake supply store, this is the favorite for wedding cakes. Not sure why, but it comes in white and ivory, so that make be a key reason (to match the bridal dress).
Truly, you should try the marshmallow version just to experience it. I've done a "lunch & learn" using the bought to cover little 4" cakes and at another one I showed how to actually make the marshmallow fondant.
Most people say they peel off the fondant at the wedding. I think that's because caterers use 1/4" thickness, which can hide a multitude of sins. I've made cakes with 1/8" thickness and it adds a nice texture. There is buttercream below to hold it on.
http://video.about.com/candy/How-to-Make-Fondant.htm