lmfao kakashi admitted that his hand seal speed was impressive that even his sharingan barely saw it, and when sauske and him fight, he mangaged to make a shadow clone while throwing shukien at sauske
Itachi was faster (pre-time-skip). When Kakashi & Naruto fought the "Fake" Itachi (Time-Skip), it was revealed that Kakashi had increased his handseal speed. I'd say they're about equal.