Luffy grew tremendously during the time skip; he is far faster, considering that he could only dodge a Pacifista laser by the skin of his teeth before the time skip whereas now he evades both the lasers and their subsequent explosions casually and even calls them slow, he has far greater power behind his attacks, as a G2 Pistol one-shotted a Pacifista, who took many and more attacks for the entire Straw Hats to take down before the time skip and a base bullet caused huge collateral damage (far more than his Gomu no Storm did at Arabasta, or even his Gear Third ever did pre-TS) by simply sending Jones flying into a huge building structure.
Not to mention that Luffy has become accomplished with Haki, and thus have pre-cog, presence sensing, ability to significantly harden his body as well as coating himself with invisible armor, boost his attack power very notably and so on.
That is, of course, only what he has shown so far, and what we can quantify. It is, however, more than enough to conclude that CP9 would be curbstomped by current Luffy - even Lucci would be blitzed and one-shotted.
