In my experience (low-end to mid-level color lasers), they are great for adding a splash of color but not great for photos. Thus color lasers are perfect for a presentation or homework where a chart might be easier to understand with lines that were different colors. But they suck at everyday home use where all people tend to print is photos.
In my experience, most lasers are quite forgiving on the type of paper. Usually you use thin paper since it saves a bundle. But I've put dense, heavy 100% cotton paper in without trouble. What can happen on some lasers is (a) a paper jam or (b) two sheets come out instead of one. The latter problem (b) is not a big deal, but a paper jam is. Some lasers are a lot pickier than others. You pretty much have to try it to know.