Both have their strengths and weaknesses, it all depends on the army you are playing. Ram armies and swarms are going to be effective against the A Drac, but is easy for the Striker to take out. Big unique armies are what the Drac likes best. If you play these figs 1v1, the Dracs got it in the bag, with her monster first rank. Plus, one shot from her puts striker past his sweet spot. I prefer the drac, but this is all opinionated.

Id prefer AD over Striker, coz of well, first strike. Second, she has lower pt cost so you can add addtional unit. Third, she is very deadly when used back-to-back with Autumn (yoyo). Her 5 damage/pierce can actually cripple any unique/multi-dial/titan and cannot be counter-attacked when yoyo'ed with a ML fig.

Amazon drac of course.:D

My vote goes to the striker.