From what I've read, 1-5 produces more follicles that are less mature, 3-7 produces moderate amount of follicles at a good maturity level, and 5-9 produces significantly fewer follicles with excellent maturity. The down side I've seen is that sometimes the follicle(s) produced on 5-9 are almost too old by the time they are released if ovulation takes place later than expected. Many doctors use the 3-7 for the best of both worlds. Then, there are some that will use whatever they have had the most success with. The 1-5, I believe, is usually for other treatments, such as IVF... but don't quote me on that. I believe they do it that way to get as many eggs as possible.
@Bsugary: Instead Cups were first marketed as a menstrual product. They look like giant condoms that are very shallow. The idea is to insert it so that the top ring sits around the cervix and collects menstrual blood. The TTC community has rather adapted it so that it is inserted after the sex to hold the sperm as close to the cervix as possible... to "keep the soup in the bowl." I've attached a pic of one of mine. I stopped using them because I couldn't figure it out... they're kind of huge! The size comparison is a U.S. penny.