I have not tried a 2003 Havoctec but I did have a 2002 model and unless I am mistaken there is not any difference other than the cam system. I would agree with your assessment about the balance and would suggest experimenting with some different stabilizers/weight combinations to see which works best for the bow. If it continues to tip backwards with your current stabilizer suggestion then you should probably look for a stabilizer with adjustable weights or that has more of a " weight forward" design to it.

As for accuracy, I had no problem shooting relatively accurately out in the 30-40 yard range with the bow. The major concern here would be canting the bow clockwise or counterclockwise and a bowsight level would remedy that situation.

Hope this helps.