I bought a dozen pastel Wilton silicone cupcake bakers when they first came out more than a year ago just to try them. It has taken me awhile but I finally used them. I baked 24 cupcakes for one of my daughter's birthday parties. [She had two this year; one with each side of the family because they live in different towns.] I have just one cupcake/muffin tin and I didn't want to hold over the second half of the batter.
Here are my observations of the silicone baking cups' performance:
1. The cakes didn't brown as dark (or at all) as the cakes in paper wrappers. Not that that is good or bad one way or the other.
2. Though the cakes pulled away from the sides of the cups as they baked, it was hard to remove them from the holders without tearing the cakes. This is because the cups have to be so sturdy so as not to collapse under the batter. You can't bend and manipulate the silicone holder as easily as paper which will yield or "give", thus leaving the delicate cake in one piece.
I am not greasing each individual cup -- I'd rather use paper liners if I have to do that.
Some "greenies" might argue for using silicone baking cups because they save the environment: They are reusable so they don't fill up dumps, they are not made of paper and therefore no trees died for their producion and they're not printed with ink that might pollute the water or soil.
My conclusion: Use these sometimes -- like when you're going to eat their contents at home and no one will expect to see a whole and perfect confection.
Decorating tip: For anyone who's interested, I was trying to top my cupcakes with frosting quickly and neatly. I decided to pipe the ivory-tinted icing in blobs in concentric circles with a No. 199 tip. I think they looked like mums. Perfect for fall!