He's faster than Minato.
Instantaneous travel from the space time jutsu is faster than anything because you can get to whatever point within your range instantly. The only thing left is for your reflexes to finish the job.
Sasuke's reflexes are much faster than Minato's. Minato was able to get to Madara thanks to s/t, but he wasn't fast enough to deliver the blow. Sasuke was able to simply blitz Madara and still cut him in half. Had he used his Rinnegan for s/t travel, he could've had enough time to cut his head off with his killer reflexes. Madara may not have even seen him coming.
Plus Sasuke can use s/t via his eye faster than Minato with having to throw kunai or set marks with slower reflexes