Since I've had it it's crashed on three separate occasions, with big green and purple blocks appearing across the screen and everything becoming unresponsive. The music I was playing at the time also blared out very loud and wouldn't turn off even with the lid closed... it took a very, very long press of the power button for it to eventually turn off. I also have the 'screen rattle' issue which occurs when lifting off the table and putting it in my bag; most annoying for a machine of this cost but I can live with that. My friend has had the same model for months and has had no such issues, despite being a much heavier user than I am. I just feel like I have a lemon and would quite like it replaced. I don't feel it's reasonable for Apple to expect me to put up with a repair when I've had it less than a week, but I've read they no longer do exchanges anymore. I plan to go to the Apple Store (UK, if it makes a difference) tomorrow, but I'm wondering if anyone on here has any similar experience and know what the course of action is likely to be? I really like the machine and it would be a shame to have to get a refund.