I was musing with my group about what would be ideal allocation of experience, characteristics, skills and virtues for a Tremere who aspired to be the "perfect duelist" - taking into account the "aggressor chooses technique, defender chooses form" and "first choice can vetoed but not the second" rules. I hope this thread will generate some input on the issue.
Ideally, you should also take into account the fighting styles from True Lineages, and assume that the character is a Harenarius; and the fact that some Arts are more likely to have been highly developed by the Order than others.
I've found that good scores in Parma, Penetration, Finesse, and Stamina are good abilities/stats.
Favoring at least one technique and one form, has also proven very effective against duelling the "generalist magi."
I have found that 3 good techniques plus secondary insight for general knowledge in the forms is good. The certamen focus means that all your forms are doubled.
You NEED 2 good Techniques and 2 good Forms. That way you should always be able to get decent scores no matter what.
The three good techniques means you are most likely covered no matter what someone challenges you. It is very good chance first or 2nd choce will be one of your stronger ones. Forms on the other hand are way too diverse when you are challenging someone. So you get scores in everything and your minor magical focus: Certamen will double it. Also gives you flexibility to avoid the best forms of your challenger since it is unlikely they have more than 1-2 good forms and you have 10 to chose from.