I just recently (two weeks ago) bought a set of cups. I looked at every cup I could find, I was really going to get the MM cups because they seemed real nice, and where not two expensive. I really would have liked to have seen some Sherwood Cups, but for the extra money, I wasn't quite sure if It was worth it.....
.....Then my friend showed me the JP cups. I ordered them that day. In comparison to the MM cups, they are a much better weight, about 2 ounces a cup. Also the lip is not folded on the JP cups, you will notice on the MM cups the lips of the cups fold over and are not one solid piece. The sound of the JP cups are also much crisper and nicer then the MM cups. I decieded if I was going to spend about $130 on cups, I might as well pay the extra $70 for the JP cups. If you don't want to spend as much money on the JP cups, the MM cups are a good set of cups, but I would not trade my JP cups for all three sets of MM cups. Just my opinion.
Also, when it comes to the balls for the cups, I didn't want to go with the Baseballs many magicians use. I contacted Mr. Jim Riser and purchased his hand made leather balls. You can see them here: http://www.jamesriser.com/Magic/LeatherBalls/Info.html
They are a wonderful weight, beautiful colors (I bought the red, they also come in an Aqua or Navy Blue) If it is OK with Mr Riser I would highly recommend these balls to you. They are slightly more than the traditional Baseballs, but worth twice what I paid for them.
Hope this helps, if you would like to further compare the JP cups with the Paul Fox check this out as well: http://store.yahoo.com/ammarmagic/comcupwhenst.html