I will just say it, the 203 is a POS! If you cruise a constant speed it feels like somebody is holding you back and letting you go and then holding you back... I love my TW 21! It is a wonderful cam and makes a huge improvement over stock even though the numbers don't look much different. Go with the TW21 but if you have to buy Harley then skip the 203 and go with the 204. It's much better! If you get a 4 degree key and a 204 you end up with a TW21. You can pull your heads and take a Dremel and take out the shelf below the valve seats. Basically remove the aluminum that sticks out from under the valve seat. Blend it in to the same diameter of the seat and you gain roughly 10 percent flow. This allows the TW21 to rev out rather well.
The difference between ignorance and stupidity is that you can fix ignorance, if you're not stupid!