I am not going to do a product review on this yet, for I have not used them enough to really know how good the quality. I only bought one package and they were on sale. I bought the chipboard ones and they don't stick very well on my layouts. They have a very nice look to them however, so I don't mind the extra effort I put into gluing them on. Here is one of my best layouts that include thickers.
If you notice that some of the letters have a little sparkle to them, then you might like to know that they did not come like that. I actually added crystal stickles over top of the thickers to make them sparkle!