Obviously Marchisio is going to offer more defensively than Pirlo in that role.
What that game didn't really show, though, was how big the gap in passing ability is between Pirlo and Marchisio.
Because Samp played an open game, it was easy for Juve to move the ball quickly and relatively simple passes were getting Juve into very good situations.
I'll be interested to see Marchisio play than role in a game where Juve are facing the sort of deep, compact, numerous defence that they face at home most of the time.