It was interesting. Fabregas had a couple of problems. First, he came into Barcelona and found a settled formation with Xavi, Inietsa, Messi and had to fit in around them. Second, he had a bit the same issue that Alexis had. While both men were supremely productive (Fabregas averaged about 25 goals + assists a season in the 3 years he was there), they struggled to slot in and operate in Borg-like manner. Fabregas preferred thee jazz-like approach that Wenger had employed at Arsenal that gave him freedom to choose his positions and approaches. At Barcelona everything was very rehearsed, something Thierry also had to come to grips with.
Eventually, the fans fell out of love with him. He was the target of boos. By the end even Real fancied themselves and wanted to rescue him. Again I blame the assholes at Barca. They should've waited 2 years for Xavi to be phased out and left Fabregas alone. Fuck them. Hope they go bankrupt.