Garrett Hack replies: Japanese saws are designed to be pulled and western saws are pushed. A pulled saw can be thin for a fine kerf since it stays taut under load. A Western saw will buckle and kink if pushed too hard, even a fine saw with a back that stiffens it.
Japanese saws have long handles and some find them easier to control to saw accurately. I think it really comes down to personal preference and what you get started with. Japanese saws have a complex tooth shape which are nearly impossible to sharpen. I regularly file my Western saws and even when less than perfect, they saw sweetly.