I’ve been using my 15″ PowerBook for more than a day now and I’m very happy with it. The large screen is a lot more pleasant to work with than the 12″ screen. The battery life seems about the same as my old 12″, although I haven’t fully re-calibrated the battery yet. I find that it runs a lot cooler than the 12″ and I haven’t heard the fan yet. I barely notice the extra weight and I can still use it comfortably on my lap. The speakers sound a lot better than the 12″.