i started a 'batting-journal' to figure out what battings i like best for different projects. when ever i see a new batt i have not tried before i get one. I cut a 4"x6" rectangle from the batt and add it to my journal. I write the name of the batt, where it came from. the price. the properties, the care instructions, and how far apart you are supposed to quilt it. After i use the batt i add what i used it for, how i liked it, how it behaved during quilting, anything else i want to remember about it...and i add pictures if i feel the need. that way if i see a batt i am not sure about i can check to see if it is one i tried once and hated...or if it was one that was really nice to work with.
I love wool batts best but they are expensive and not always appropriate. i usually use poly or poly/cotton blend batts for kids and utility quilts that will take alot of abuse and get laundered alot. for quilts that may still be used regularly but wont be really abused i like a good cotton if i don't want to put out the extra $$ for wool or silk. I also like the bamboo blend batts. i like to try new ones as they become available. the new "green-batt's " hold up well to much abuse and are good for kids quilts. they are usually inexpensive and they are made out of recycled materials. they wash up well ...the only down side i found with them was.....they are green,,,, so not so great if you have a quilt with a lot of white....anyway--- try them all as you are able...and make a journal it may prove to be a valuable tool.