Batting is all a matter of personal preference. It's not just about how lofty it is. The more natural fibers "breathe" and will not vary that much in being good for one season or the other. Some quilters use more than one layer of batting in order to achieve both the "natural fiber breathability" and more loft to show off the quilting. [Another way to achieve this effect is to use cotton thread which will shrink with the unwashed fabric in the quilt.]
Polyester high-loft batting will retain its loft, is antimicrobial, and doesn't absorb moisture (does not wick). It doesn't breathe (and therefore is too stuffy for those who are naturally warm). It is also relatively low-cost. Polyester batting is not recommended for small infants.
Bamboo blend batting is the same loft as warm and natural or 80/20 cotton blend batting. The advantage of bamboo blend batting is that it is antimicrobial (bugs will not lay eggs in it).
Wool batting will keep its high loft and still gives you that "natural fiber breathability". It also costs almost twice as much as some other battings.
Just feeling the batting itself doesn't give you enough information. Handling something quilted with the different kinds of batting gives you more of the "tactile" information that you need.