Xavi is one of the players who have a crucial role in the success of Barcelona tiki-taka in Pep era. As far as I understand, there were 3 players who have the most roles at that time, they are Xavi, Iniesta, and Messi.
Xavi is a home grown player from La Massia and he is part of golden Tiki-taka era years ago. More than other coaches, Xavi understands comprehensively on how tiki-taka works but he also knows that at the end of golden time, tiki taka was constrained by other clubs.
Therefore he does know that he must use enhanced version of tiki taka if he want to get success. From players bought by Barcelona with transfer strategy from Xavi, I see that he tries to bring more speedy and powerful players. He does want to get more direct attacking and more powerful physically to prevent counter attacks from opponents. It is a good strategy that can bring success for Barcelona and Xavi.