c'mon guys be serious.
Both of them are revolutionary, both are easy to use, and both have great services for if you want to obtain any help,.
I personally use XBC, and although i have nothing personal against Kai, there is a good group of people who i play regular on XBC.
I tried running both, so when there wern't many games on XBC i could use Kai, however installing Kai, prevented XBC from running and i had to do a system restore to before Kai was installed for XBC to run again,
Don't know if it was something interpreted to the new Kai, but because of this it's put me off using Kai alongside XBC,
Regardless both are great and i say stick with what your used to, and if your a noob, then give them both a try.
check out the TBD clan site. as seen on XBC
TBD (xbc clan)