Pirlo was a much better long passer than Xavi, and more penetrative close to the final third. More elegant, better at set pieces and shooting.
He's a level below though. Where Pirlo had issues with aggressive pressing, off the ball work and had a bit of a mercurial temper, Xavi was basically flawless in his role. It didn't matter what the opposition did, you couldn't force him into making a mistake. Even pressing him into making a less than ideal pass was rare. His composure, decisionmaking, movement and assurance in his passing is just unparalleled
There has never been a player who could link play from defence to the final third in a way that translated to automatic total midfield dominance every damn time he stepped on to a pitch, the way Xavi did for six years straight. Put a prime matthaus on any opposition team against him and Xavi would still play him off the park the way he did every midfield during that period. No one in football history has come close to the kind of midfield dominance Xavi exerted. Not in how overwhelming and comprehensive it was, nor in how consistent or how many years he held that level. That for me makes him the best midfielder of all time.
His only real shortcomings were that there were times against packed defences where you'd want him to step up a bit more in the final third and he didn't have the engine or dribbling for that. If mourinhos inter had done to iniesta what they did to Xavi, just stand off him and get everyone to close off his passing lanes, iniesta would have murdered them with that kind of space to run in and Xavi couldn't do that. Still, it is very very few games over a long peak where he's been out maneuvered.
Baffling that anyone would bring Scholes into such a discussion but that's the caf for you.