It seems like people are afraid to use this unit,its actually quite simple im 17 and this is my first turbo car and i tuned mine my self, here is some help i used from someone on honda-tech http://www.honda-tech.com/zerothread?id=1037051.
also this is the gearing for a 2004 wrx:
1- 3.454:
2-1.947:1
3- 1.366:1
4- 0.972:1
5- 0.738:1
and this is the gears for a 2004 sti:
1st: 3.636
2nd: 2.375
3rd: 1.761
4th:1.346
5th:0.971
6th: 0.756
reverse: 3.545
hope this info helps and good luck.