Check about halfway down this page and it highlights the differences within the model range.
You're talking about this?
"Compact head with high operability and smooth swing"? "The practical iron which added flying distance performance"?
Different lofts, same offset, and a difference of .6mm blade thickness is all I can make out from that. What are is the bounce in these heads? Are there differences in the sole thickness & camber? Blade length & height? Are there slight differences in forgiveness vs. workability?
You can also click on each variation on the lefthand side of the page and "specs" to get more of the numbers you are looking for. As far as forgiveness vs workability, VN should be most workable, VS most forgiving, and V in the middle.