Bio 500T have very different balance from Bio 400T. But it still swings easy on the court. So far i prefer 400T, but next week i will try 500T with full poly and i'm really intereseted how it will perform.
Btw i'm thinking about getting 200 Lite too, I like the specs and it's very cheap in my country right now.
Bio 400 Tour - Yonex PTP (1.25) 51/49 lbs, Youtek Prestige MP - SP Tornado (1.17) 46/44 lbs