I tend to buy mens jerseys because I am rather apple shaped and womens jerseys just don't take that into account--even in plus sizes. This means I have to put up with arms that are too long in long sleeve styles. On the plus side, mens jerseys have a longer belly covering length. I don't know if any of these issues pertain to you, but it works out better for me to go to a bigger in mens.

another thing to consider is if the jerseys are club cut or racing cut. Club is more generous and racing cut assumes you have a Tour de France type body.