Vidal replaces Davids for me, but it's all about taste in the end. Davids was a phenomenal midfielder and we're a great club with a rich history consisting of many greats, so there are plenty of great players to choose from. In fact, we've had so many great players that you can't really say that there's a "right or wrong" in these matters, as long as you make sure that you have picked a player that was definitely world class. Davids was world class, but so is Arturo Vidal.
To me, Vidal is someone who comes close to David's defensive skills. Not saying he's Davids' equal in defensive terms, but he's pretty damn close! But what makes Vidal stand out, for me, is the attacking dimensions of his game, which are a level above those of Edgar Davids.