Alonso and Fabregas are indeed completely different players. The way I see it Xabi is the better passer (no slight on Fabregas who is an excellent, incisive passer - Alonso is just as good as anyone in the game) and a more intelligent, thinking footballer who is more likely to stay around the centre area of the pitch and dictate play from there. Fabregas on the other hand is more all-action, 'box-to-box', likely to be involved winning the ball, then getting forward into the oppositions penalty area and be directly involved in goals either delivering a short killer pass or scoring himself. Both are fantastic talents - each fits into his role within their respective teams perfectly and you could argue either player's case; but I wouldn't swap our Xabi for Fabregas or anyone else personally.