If I may interject my opinion, I am highly doubtful that Tai Chi has much of anything to do with Aikido. Like has been stated before, the Japanese arts evolved and continued to do so throughout it's history. When O'Sensei was in China, I doubt he began training in it's arts. Although there are similarities, many different countries have differnt arts that have techniques that look the same. Tae Kwon Do, Tang Soo Do and Karate. They have many similar techniques. But in history, the roots are some what different. It is true Daito Ryu had much to do with Aikido, almost as the direct influence. However, Spear and Sword did as well. Of course these are all things that O'Sensei learned in Japan. And he continued to refine these skills forming what would eventually be called Aikido. Sorry to have rambled on with this, and to those I have bored, sorry. But I hope as a martial arts community all styles can get along. I do not beleive there is one truly better than the other. Just a matter of personal preference.