both clients are garbage nowdays, BitComent is just an absolute disgrace. Although it doesnt use java is it still quite heavy on resource usage, also its p*ss poor implmentation of DHT/Peer Exchange has caused it to be ban on nearly every major tracker site i use. Azureus is a great client and has alot of things that can be done with it, its only let down is the heavy resource usage due to the java runtime environment, its still the best overall client purely because its cross platform. if you want a windows client then there is no other choice but µTorrent as it easily outperforms any other.