I would post a message because I would buy a mac air but I have some questions about performance. In fact I know that there are 2 models, one 1.6 GHz and 1.8 GHz one, but what are the real differences in performance? Is this is a gain in speed of launch programs, better performance of soft a bit greedy, or a faster start? I just know that the model offers a 1.8GHz 128GB SDS allowing greater transfer speeds and data reading and a little autonomy. Sp, basically I need to know the Macbook Air performance? Any advice on this is appreciated. Thanks in advance.